Program

9:00-9:20 a.m.: Understanding and Enhancing PET Hydrolysis for Sustainable Chemical Recycling through Integrated Experimental and Molecular Dynamics Approaches

Max Ma*, Patrícia Pereirab, Phillip E. Savage, Christian W. Pester, Bhavik R Bakshi, Li-Chiang Lin 

Ohio State University

Polyethylene terephthalate (PET) is a widely used polymer in consumer goods, especially in packaging, but its accumulation in the environment poses significant sustainability challenges. Chemical recycling through hydrolysis offers a promising solution by breaking PET down into its monomeric components, such as terephthalic acid (TPA) and ethylene glycol (EG), which can be repurposed for new PET production. Despite the potential, the detailed mechanisms behind PET hydrolysis and the formation of various byproducts remain poorly understood, limiting the optimization of recycling processes.
This study combines experimental methods with Reactive Molecular Dynamics (ReaxFF-MD) simulations to investigate the molecular-level processes occurring during PET hydrolysis. Experimentally, virgin PET pellets were hydrolyzed under controlled high-temperature conditions, and the products were quantified using High-Performance Liquid Chromatography (HPLC). Simultaneously, ReaxFF-MD simulations provided a dynamic view of the bond-breaking and formation processes, enabling the identification of key intermediates and reaction pathways.
Our findings revealed that while TPA and EG are the primary products, bis(2-hydroxyethyl) terephthalate (BHET) acts as a crucial intermediate. Notably, the simulations demonstrated that TPA plays an autocatalytic role, enhancing the overall hydrolysis process. A dual mechanism of degradation involving both hydrolysis and thermal cracking was identified, particularly at elevated temperatures, leading to the formation of byproducts such as glyoxal and formic acid. The integration of experimental and simulation results also highlighted the influence of temperature and pressure on the yield of hydrolysis products, providing critical insights for optimizing reaction conditions.
This work presents a comprehensive approach to understanding PET hydrolysis, bridging the gap between theory and practical application. By combining molecular simulations with experimental data, we offer new insights into how reaction conditions can be tailored to enhance the efficiency of PET recycling and contribute to the broader goal of developing sustainable polymer recycling technologies and addressing the environmental impact of plastic waste.

9:20-9:40 a.m.: Polyolefin adsorption on catalyst supports for chemical recycling

Fawaz Motolani*, Rebbekah J. Snellings, Sogand Aghamohammadi Ghadilou, Gina Noh, Bert Chandler, Bryan D. Vogt 

Penn State University

Catalytic upcycling of polyolefins through deconstruction into value-added products represents a route to economically incentivize recycling of plastic waste. However, despite promising reports on batch systems, there remain challenges in scaling due to knowledge gaps in the mathematical descriptions of the reactions, including transport limitations, size dependence of adsorption and desorption dynamics, and catalyst deactivation rates, which will control the product distribution and ultimately the product value. Catalyst deactivation is commonly described by coking that results from the aromatization of adsorbed species. Here, we investigated the deactivation by examining the material adsorbed to a model hydrogenolysis catalyst, Pt on silica, under low hydrogen pressures to promote coking. FTIR analysis of the organic residuals on the catalyst found no signs of aromatic species only hydrocarbons. Similar levels of residual organics were found on the silica support without Pt metal, which combined with FTIR suggests irreversible adsorption on the support surface. To better understand this adsorption behavior, polyethylene and its oligomeric analog, hexatriacontane, were heated at 250 °C with the silica support at different times. Following typical solid extraction methods reported in the literature led to two-step loss in TGA; Even with hexatriacontane, the TGA exhibited a lower temperature loss that is consistent with the neat hexatriacontane and a higher temperature loss. Extended extraction of the silica in xylene at 120 °C removed approximately the same amount of hydrocarbon that was lost at the lower temperature step in TGA. These results indicate despite the lack of strong functional groups polyethylene can effectively adsorb irreversibly to silica surface. These findings highlight the potential for strong adsorption of polyolefins on catalyst supports, a factor often overlooked in modeling catalytic upcycling processes. Our results suggest that deeper understanding of polymer-support interactions may improve catalyst design and the efficiency for the catalytic chemical recycling of plastics.

9:40-10:00 a.m.: Photothermal Conversion Depolymerization of Commercial Plastics

Hanning Jiang*, Sewon Oh, Erin Stache 

Princeton University

Photothermal conversion is an emerging technique in combating plastic pollution. Here, we developed a photothermal system using lab-made polystyrene-carbon black (PS-CB) composites and achieved up to 60% isolated styrene monomer yield under white light irradiation. Post-consumer waste plastics were photothermally depolymerized employing black pigments in commercial plastic products. Under focused sunlight irradiation, black polystyrene plastics were fully depolymerized in 5 minutes, with up to 80% styrene monomers, showing promising potential for real-world application.

10:00-10:20 a.m.: Functionalization of oligomers from recycled post-consumer plastics

Alison Biery*, Shelby Watson-Sanders, Christy Witcher, Brian K. Long, Mark D. Dadmun 

University Of Tennessee, Knoxville

Chemically breaking down plastics into species which can be incorporated into novel polymer materials is one method for producing value-added products from the recycling of post-consumer polymers. Our group has developed methods for recycling commercial poly(ethylene terephthalate) (PET) and polycarbonate (PC) into oligomers of controllable molecular weight and functionality. This work presents the modification of PET and PC oligomers to difunctional telechelics, which are suitable for incorporation into multiblock copolymers. The telechelics can be reacted with oligomers of other common consumer polymers to produce copolymers over a range of compositions. The resultant multiblock copolymers are of interest as compatibilizers for the further recycling of incompatible polymer blends. Functionalization of the PET and PC oligomers with groups that may be incorporated into dynamic covalent bonds is also under investigation as a method for producing vitrimers from recycled polymer materials.

10:40-11:00 a.m.: Leveraging feedstock selection and characterization in lignocellulosic biorefineries for the production of sustainable polymers

Alison Shapiro*, Thomas H. Epps, III

University of Delaware

Lignocellulosic biomass (LCB) has emerged as a promising alternative feedstock to alleviate the sustainability concerns associated with petrochemical-based products, such as chemicals, fuels, and materials. A major hurdle for LCB valorization is the heterogeneity and compositional variability among feedstocks, which is particularly challenging for forestry, agricultural, and other underutilized LCB residues. These residues are optimal biorefinery feedstocks because they are available at low costs in large quantities with minimal environmental harm. In this work, approaches to enable informed feedstock selection and leverage advanced characterization have been developed to enhance the economic and environmental viability of LCB biorefineries. Structural carbohydrate (cellulose, hemicellulose) and lignin content in forestry residues was quantified for different constituents (bark, twigs, foliage) of multiple species and across phenophases. Cellulose and hemicellulose content, in conjunction with neutral sugar analyses from stemflow samples, then was used to develop a conceptual framework for sugar cycling that could be applied to optimize harvest schedules for biorefineries. Phenolic monomeric deconstruction product yields and distributions from reductive catalytic fractionation (RCF – the most common lignin-first deconstruction strategy) from the same set of forestry residues also were measured. Lignin content and RCF phenolic yields and product distributions were assessed to identify additional opportunities for harvest optimization and suggest routes to maximize lignin valorization. After demonstration of the potential for feedstock informed biorefinery optimization, two higher throughput, low-cost LCB screening approaches were developed – one harnessing the optical properties of dissolved organic matter in stemflow and another applying a thermogravimetric analysis approach. Both strategies can obtain LCB compositional information and predict RCF outputs, enabling biorefinery product management and proactive process optimization. Together, the approaches presented in this work inform feedstock selection, screening, harvesting, and valorization, ultimately providing a pathway towards the industrial success of lignocellulosic biorefineries.

11:00-11:20 a.m.: Algae-Guayule Latex Biocomposites: Characterization and Mechanical Analysis for Sustainable Material Development

Siddharth Premnath*, Chiara Daraio, Julia Kornfield

California Insistute of Technology

Biocomposites are materials composed of natural fibers, such as those from crops and plants, embedded in a matrix or binder derived from substances like cellulose, starch, and lactic acid. They offer an eco-friendly alternative to traditional petroleum-based materials, boasting benefits like reduced environmental impact and the use of renewable resources. However, current biocomposites still rely on the extraction and processing of fibers, which often require harsh thermal, mechanical, and chemical treatments. These processes not only consume significant energy but also can degrade the natural fibers, potentially compromising the mechanical properties and longevity of the final product. A new approach to creating biocomposites involves utilizing the entire plant biomass for compression and thus significantly reducing the waste and energy requirements compared to traditional methods. Algae is a promising candidate owing to its abundant availability as a waste material from various industries, and its high biomass yield and ease of cultivation make it particularly suitable for sustainable material production. In addition to algae, we use natural rubber to improve the toughness and impact resistance of the biocomposite. This natural rubber comes from Guayule (Parthenium argentatum), which is a perennial shrub native to the arid regions of the southwestern U.S. and north-central Mexico. The produced natural rubber (cis-1,4-polyisoprene) is similar to the rubber from Hevea brasiliensis. However, unlike H. brasiliensis, guayule does not contain the allergenic proteins that cause type 1 latex allergies. Additionally, argentatins, which are secondary metabolites synthesized by Guayule, have been shown to have numerous potential medical applications. These include their cytotoxic activity against human cancer cells and their insect-repellant properties. We vary the processing conditions and characterize the microstructure and mechanical properties of this biocomposite using SEM, TEM and FTIR, compression/tension testing and three-point bending tests.

11:20-11:40 a.m.: Bio-based Additive Manufacturing as a Valorization Pathway for Enzymatically Recycled Cotton Textile Waste

Isabel Albelo*, Sonja Salmon

North Carolina State University

Apparel waste management is a global challenge that is becoming increasingly dire with the rise of fast fashion supply chain models, resulting in the projected accumulation of gigatons of textile waste in the world’s landfills. Moving towards textile circularity would divert waste from landfills, reduce dependence on carbon- and resource-intensive virgin materials, and serve as an opportunity for important value retention of these highly engineered materials. However, textile recycling is challenging due to the difficulty of separating complicated apparel products and fiber blends into useful waste streams. Enzymes present a potential solution because, together with simple filtration, they are adept at separating fiber blends (unlike mechanical recycling techniques such as shredding) due to their substrate selectivity (i.e. extracting cotton fragments form a cotton/polyester blend while leaving the polyester intact). NCSU’s Textile Biocatalysis Research group has developed an enzyme-mediated process to efficiently degrade the cotton components of model apparel materials into slurries of microscale cotton fiber fragments (CFFs) and soluble sugars under mild reaction conditions. In addition to attractive cellulose attributes such as biodegradability, thermomechanical stability, and readily modified chemical functionality, the residual CFFs are highly crystalline and have dimensions that are suitable for the development of bio-based additive manufacturing feedstocks. The focus of this research will be to reassemble the enzymatically degraded microscale fragments into industrially relevant, bio-based macroscale objects (such as structural meshes and grids for apparel, footwear, and home furnishings) via 3D printing. Rather than disrupting the CFF crystallinity, as occurs during dissolution to make viscose or lyocell, the fragments will be suspended in extrudable liquid media, with minimal added compounds, and then coalesced to achieve structural integrity. The fabrication of proof-of-concept cellulosic bioink printed prototypes will serve to demonstrate a potential pathway for commercial valorization of the waste cotton fiber fragments and incentivize industrial textile waste recycling.

2:00-2:20 p.m.: A Systematic Approach to Assess the Size-Dependence of Polystyrene Model Microplastics on Human Serum Albumin

Kateryna Rudich*, Daniel Sebrosky, Andriy Voronov, Mohiuddin Quadir

North Dakota State University

The increasing production and consumption of plastics have led to widespread accumulation of micro- and nanoplastics (MNPs) in the environment, posing potential risks to human health. Mechanistic understanding of how MNPs interact with human blood proteins is crucial for assessing their toxicity. Using human serum albumin (HSA) as a model protein and model polystyrene (PS) latexes of varying particle size distribution (PSD) as a representative MNPs candidate, we aim to deconvolute how size, shape, surface charge, and chemistry affect protein structural properties. PS latexes were synthesized via surfactant-free emulsion polymerization to eliminate presence of additional (surfactant) molecules on particles surface, while controlling PSD by varying polymerization conditions. Fluorescence quenching experiments and circular dichroism (CD) spectroscopy were used to assess the effects of model polystyrene particles (PS MNPs) on protein structure. Our findings demonstrate that the interaction between PS MNPs and HSA induced changes in the microenvironment of the tryptophan (Trp) residue in HSA, affecting its fluorescence. The fluorescence of HSA was more effectively quenched by smaller PS MNPs, indicating they impact HSA structure more significantly. The obtained results provide insights into the size-dependent interactions between PS MNPs and HSA, shedding light on the predictive toxicity associated with plastic pollution. The long-term research objective is to produce additive-free model MNPs from various polymers as controlled reference systems for better understanding the interaction landscape of MNPs with physiologically-relevant proteins.

2:20-2:40 p.m.: Morphology-Dependent Ionic Conductivity in Block Copolymers Based on Polymer Ionic Liquids

Samuel Kpakpo Junior Adotey*, Yangyang Wang, Gila E. Stein

University of Tennessee

Block copolymer electrolytes (BCPs) made of nonionic polymers linked to polymer ionic liquids (PILs) are a promising class of electrolytes for energy storage and conversion devices. However, our previous studies have shown that the bulk ionic conductivity of certain lamellar-forming materials is significantly lower than the expected values based on the ionic conductivity of the PIL homopolymer, the composition of the BCP, and the self-assembled morphology of the BCP. We hypothesized that this lower ionic conductivity may be due to poor connectivity among ionic domains in the lamellar phase, diffused block interface, or the difference in glass transition temperature between the PIL homopolymer and PIL block in the block copolymer. To test this hypothesis, we examined the ionic conductivity in highly asymmetric (spherical and cylindrical morphologies) and lamellar BCPs with a majority PIL phase. We found that the normalized ionic conductivity in spherical and cylindrical BCPs met or exceeded the predicted values. Notably, the ionic conductivity of some highly asymmetric BCPs exceeded that of the homopolymer PIL. This effect may be attributed to enhanced decoupling of ion transport and segmental dynamics in the confined BCP domain.

2:40-3:00 p.m.: Alternative Solvent Systems for Metal-Free Ring-Opening Metathesis Polymerization

Brittany Trinh*, Alexis D. Garbisch, Ryan J. Ryzner, Andrew J. Boydston

University of Wisconsin-Madison

Ring-opening metathesis polymerization (ROMP) is a type of olefin polymerization that retains the unsaturation of the monomer in the polymer backbone. ROMP has been traditionally achieved with metal alkylidene initiators (Ru, Mo, W), with the residual metal retained in the final polymer. One method to eliminate metal species in polymers is metal-free ring-opening metathesis polymerization (MF-ROMP). In MF-ROMP, a photoredox catalyst and organic initiator generate a radical cationic species to initiate polymerization when irradiated with blue light. Typically, this reaction is done in dichloromethane (DCM), but there has been increased interest in reducing DCM in industrial chemical processes. Therefore, we seek to identify alternative solvent systems for MF-ROMP to make it more environmentally friendly polymerization while understanding the properties that make a solvent suitable for MF-ROMP. We demonstrate the effects of different solvent systems on MF-ROMP for a few industrially relevant ROMP monomers.

3:00-3:20 p.m.: Withdrawn

3:20-3:40 p.m.: Functionalization of [2Fe-2S] Metallopolymer Electrocatalysts through Click Chemistry

Arthur Gibson*, Richard S. Glass, Dennis L. Lichtenberger, Jeffrey Pyun

University of Arizona

Efficient storage of energy from renewable sources such as wind and solar is a necessity due to their intermittent nature. An excellent candidate for energy storage applications is hydrogen (H2) as it is a carbon-free, high-density energy carrier that can be formed through electrolysis. We have shown that polymer-supported [2Fe-2S] clusters containing protonated amine sidechains electrocatalyze the hydrogen evolution reaction (HER) in an aqueous TRIS buffer solution at pH 7.0 at a rate comparable to a standard platinum electrode. In an attempt to increase the functionality of these metallopolymers, azide containing monomers were incorporated into the polymer backbone to allow for post-polymerization functionalization through click chemistry. These new metallo-co-polymers were then successfully reacted with varying acetylene containing groups while retaining the integrity of the [2Fe-2S] active site. Electrochemical analysis shows that these metallo-co-polymers remain active towards the hydrogen evolution reactions, proving the functionalization of the polymer backbone is a viable method towards improvement of [2Fe-2S] metallopolymers electrocatalysts.

3:40-4:00 p.m.: Photothermal ATRP via Vitamin B12 Derivative

Cristina Preston-Herrera*, Sajjad Dadashi-Silab, Erin Stache

Princeton University

Cobalt has been mainly used in controlled radical polymerizations under organometallic mediated polymerization methods. Recently, our lab has reported on this use of a vitamin B12 derivative, heptamethylester cobyrinate (HME-CN), to act as a catalyst for atom transfer radical polymerizations. Under visible light activation, this catalyst will undergo non-radiative relaxation to the ground state, releasing energy in the form of localized heat. Transient absorption spectroscopy showed excited state lifetimes of 36 ps, ruling out HME-CN activating polymerization in the excited state. Photothermal localized heating quickly dissipates without light irradiation; this was leveraged to shows temporal control of the polymerization. HME-CN was then modified with axial ligand coordination using thiolates to facilitate ligand-to-metal-charge-transfer (LMCT) for the regeneration of the catalyst under red light irradiation. Here, we have shown the duality of a vitamin B12 to act as a ATRP catalyst and a photothermal agent across a broad range of wavelengths.

9:00-9:20 a.m.: Multilayer Co-Extrusion: An Additive Manufacturing Method to Impart Improved Mechanical Properties to Recycled Polyolefins

Joel Linebach*, Gary E. Wnek, Ph.D.

Case Western Reserve University

With plastic production growing exponentially, adapting to new processes to decrease plastic waste is imperative to managing the ecological consequences of the world’s current waste problem. Multiple pieces of literature in polymer research look towards chemical decomposition processes that separate, break down, and recycle polymer materials back to their fundamental oligomers to be reprocessed. Upcycling is also a method of recycling that increases a given material’s life span, though upon further and continued processing, bulk polymer materials, specifically thermoplastics, experience a decrease in working properties like elastic modulus, tensile strength, and toughness.
Multilayer Co-Extrusion is a single-screw extrusion process that involves ‘multipliers’ to cut and stack the polymer extrudate in situ to create complex, highly layered film architectures. As the number of multipliers in the extrusion line can be altered, specific architectures are achieved regularly in this additive manufacturing process. Depending on the number and alignment of the multipliers, highly layered 1D systems are created with layer thickness ranging from the micron to nanometer dimension, and 2D systems of ribbons are produced with dimensions in the micron range.
During 1D and 2D multilayer co-extrusion, incompatible materials, for example, polyethylene and polypropylene, can be processed together to create a film or matrix of ribbons, respectively, that undergo a degree of crystallization through spatial layer confinement, if rheological requirements are met. If a heated draw is performed post-extrusion, the material's thermal and mechanical properties are significantly increased compared to the raw material due to the physical alignment of polymer chains. This forced assembly coextrusion process can reprocess commonly recycled plastics in an inexpensive, simple, high-throughput method that imparts improved mechanical and thermal properties to otherwise low-value, “waste” material. The produced films and ribbons may be further processed into recycled composite reinforcement, non-woven fabrics, or high-performance filters/membranes.

9:20-9:40 a.m.: Targeted Separation Scheme of Polyurethane Depolymerization Products

Taysha Telenar*, Matthew Green

Arizona State University

In the United States, end-of-life polyurethane foams such as mattresses or cushions go predominantly to landfills. Mechanical recycling can prolong the inevitable fate of these materials, but not indefinitely. An emerging option is chemical recycling: breaking down these foams into smaller re-polymerizable feedstocks to create a polyurethane circular economy. Chemical recycling creates a chemical mixture, requiring separation mechanisms to produce contaminant-free feedstocks. The proposed separation methods utilize membrane technology through various processes, such as pervaporation and filtration, because these processes require lower energy. 
This study investigates the separation of degradation products from model polyurethanes. The model compounds considered are a poly(methylene diphenyl diisocyanate)-co-(1,4-butanediol) (pMDI-BDO) and a poly(MDI)-co-(bis(2-hydroxyethyl) terephthalate) (pMDI-BHET). Methanolysis of the MDI-BDO model compound yields a mixture of MDI-dimethyl carbamate (MDI-DC), BDO, a potassium tert-butoxide (KOtBu) base, methanol (MeOH), and water from washing. Methanolysis of the MDI-BHET model compound can be controlled to give a mixture of MDI-DC, BHET, terephthalic acid (TPA), ethylene glycol (EG), KOtBu, MeOH, and water. 
Leveraging each component's distinct physical and chemical properties allows for a targeted separation strategy using the above membrane systems. Dimethyl carbamates' insolubility in water and methanol allows them to be efficiently removed with microfiltration membranes. Pervaporation effectively targets removing the less volatile liquid components like BDO and EG. Finally, pervaporation can also be applied to the final separation of the water:MeOH mixture. To evaluate the effectiveness of microfiltration membranes, binary mixtures of each component with either MeOH or water were tested. Microfiltration effectively removes MDI-DC from both MeOH and water mixtures. BDO and EG permeate through microfiltration membranes and are effectively captured by subsequent pervaporation, removing them from MeOH and water.

9:40-10:00 a.m.: Liquidlike low-friction polymer brush finishes for textile microfiber shedding reduction

Sudip Kumar Lahiri*, Zahra Azimi Dijvejin, Farzan Gholamreza, Sadaf Shabanian, Behrooz Khatir, Lauren Wotherspoon, Kevin Golovin

University of Toronto

The laundering of synthetic textiles is the primary source of ocean microplastic pollution. During washing, rubbing between fibers or against the washing machine, exacerbated by the elevated temperature, initiates microplastic fibers (MPFs) release. Due to their small size, MPFs cannot be effectively removed, allowing them to reach marine ecosystems and damage aquatic life. We designed a fabric finishing strategy for synthetic textiles that efficiently minimizes the MPF shedding after repetitive washing. We showed that when the coefficient of friction is below a threshold of 0.25, the MPF reduction was significant, up to 96%. This finishing strategy involved the modification of nylon and polyester fabrics by creating a two-layer coating system. The primary layer was the ionic bonding of sulphonic acid-terminated trimethoxysilane (MPTMS) molecules on nylon and the covalent bonding of 3-aminopropyltriethoxysilane (APTES) molecules on polyester fabric surfaces. Then, the secondary layer of low friction liquidlike polymer brushes, such as hydrophobic polydimethylsiloxane (PDMS) and perfluoropolyether (PFPE) brushes and hydrophilic polyethylene glycol (PEG) brushes were grown on top of the primed nylon and polyester fabrics via vapor and solution phase deposition. The number of MPFs released from the bare fabrics was compared to those coated with only the molecular primers, polymer brushes, or two-layer primer-polymer-brush coatings for nylon and polyester fabrics. The MPTPS-PDMS, MPTMS-PFPE, and MPTMS-PEG dual-layer coating systems reduce the amount of microfiber released from nylon fabrics by 94%, 91%, and 88%, respectively, after five laundering cycles as compared to the bare fabrics. Furthermore, for polyester, the APTES-PDMS, APTES-PFPE, and APTES-PEG systems showed 86%, 96%, and 84% MPF reductions compared to the bare fabrics. The primer-polymer-brush coated textiles also maintained comfort properties and excellent durability. Thus, our work provided a general solution to reduce the microplastic fiber shedding from synthetic textiles and contribute to developing a sustainable textile industry.

10:00 a.m.-10:20 a.m: Sustainable Vat Photopolymerization of Complex Functional Structures with Fast Dissolvable and Recyclable Supports

Saleh Alfarhan*, Kailong Jin, Cindy (Xiangjia) Li

Arizona State University

Vat photopolymerization (VPP) 3D printing technology enables the creation of highly precise structures at rapid speeds. However, fabricating complex designs, especially those with overhanging or free-hanging features, often requires extensive support structures. These supports can be difficult to remove, leading to labor-intensive post-processing, surface imperfections, and potential damage to the final product. While materials such as NaOH-soluble substances and wax have been used for removable supports, these approaches are limited by material compatibility and generate significant waste. Traditional VPP processes utilize photocurable liquid resins that form permanently crosslinked polymers, resulting in non-recyclable waste, particularly from support structures. This study addresses these challenges by exploring the use of crosslinked thiol-ene photopolymers, such as polybutadiene and polyisoprene, known for their robust mechanical properties. The innovation lies in employing liquid polydiene elastomer as a base for chemically recyclable resins in VPP 3D printing. By utilizing photoreactive thiol end groups and dynamic disulfide bonds in liquid polysulfides, these materials undergo photoinitiated thiol-ene reactions with polydiene’s carbon-carbon double bonds. The resulting crosslinked elastomers are capable of undergoing base-catalyzed thiol-disulfide exchange reactions, enabling decrosslinking into reusable photoreactive thiol oligomers. Combining these recyclable resins with conventional resins allows for the creation of multi-material structures, including intricate overhangs like microfluidic channels and interlocked drones. The study also investigates the effects of surface-to-volume ratios and crosslinking rates on recycling efficiency, optimizing porous support structures for easy removal and recyclability. This scalable approach demonstrates a sustainable solution for fabricating complex structures with removable, recyclable elastomeric resins via VPP. It offers an environmentally friendly alternative to traditional casting and molding methods, advancing 3D printing toward more sustainable manufacturing practices while maintaining material properties across multiple recycling cycles.

10:40-11:00 a.m.: Development of a fibrous, reversibly-crosslinked, hydrogel composite with temporal control of magnetically-induced fiber alignment

Grace Schwarz*, Julianne Holloway

Arizona State University

Approximately 14 million fibrous connective tissue injuries occur annually in the United States.1 These ligaments and tendons are comprised of highly organized tissues.1 During healing, disorganized tissue with inferior mechanical properties forms.1,2 For connective tissues, fibers and fiber alignment serve as a critical physical signaling cue to direct cell morphology and gene expression.2,3 Further research is needed to better understand the temporal role of these physical cues on cell behavior and new tissue formation. 
To address this, we designed a magneto-responsive fiber-hydrogel composite with temporal control over fiber alignment. Magnetic nanoparticles were incorporated into short, electrospun, fibers to enable alignment in the presence of a magnetic field. Fibers were combined with guest-host hydrogels, then we characterized fiber alignment as a function of fiber length, magnetic field strength, and magnetic field exposure time. 
Fibers did not affect the hydrogel’s viscoelasticity. Fibers aligned within the hydrogels in the extended presence of a strong magnetic field, demonstrating that the magnetic field generates sufficient shear stresses to break the dynamic crosslinks, enabling fiber movement. Fiber alignment was visible after 30 minutes of exposure and continued to increase until plateauing at 120 minutes of exposure. Fiber alignment was not affected by fiber length. Temporal control over alignment was shown by first aligning fibers horizontally and later aligning fibers vertically by changing the magnetic field orientation. 
Critically, dynamic fiber-hydrogel composites with magneto-responsive fibers enable in situ control over fiber alignment at any user-defined timepoint via the application of a magnetic field. This system will allow us to investigate the temporal role of fiber alignment on cell behavior. Ongoing work is evaluating cell behavior as a function of dynamic fiber alignment within these fiber-hydrogel composites.
References: 1Yang G. Birth Defects Res. C Embryo Today. 2013;99:203-222. 2Petre DG. Tissue Eng. Part B Rev. 2022;28:141-159. 3Omidinia‐Anarkoli A. Small. 2017;13:1702207.

11:00-11:20 a.m.: Utilizing surface-initiated atom transfer radical polymerization to fabricate well-defined magnetic polymer nanocomposites

Lindsey Holmen*, Jeffrey Pyun

University of Arizona

Surface-initiated atom transfer radical polymerization (SI-ATRP) has emerged as a versatile and controlled method for surface modification of nanoparticles, flat substrates and other solid supports to generate stable nanocomposites. Controlled radical polymerization (CRP) techniques, like SI-ATRP, has gained popularity for a wide range of fields due to its ability to precisely control polymer chain length and architecture. The fabrication of hybrid materials comprised of magnetic/polymeric nanocomposites using CRP has been reported; however, challenges remain in preventing particle aggregation due to strong magnetic dipole-dipole interactions and achieving high grafting density. To achieve uniform particle distribution, hexagonal arrays are desired, but with large ferromagnetic nanoparticles, a dense polymeric coating is required to suppress 1-D assembly and promote uniform structures, thereby enhancing transparency. In this study, we will present the development of a method for functionalizing ferromagnetic nanoparticles via SI-ATRP, enabling precise control over interparticle spacing uniformly, while achieving high grafting density, uniform hexagonal packing, and sufficient colloidal stability.

11:20-11:40 a.m.: Machine Learning-Based Monitoring of Nanofiller Alignment Under Electric Field

Tengteng Tang*, Namratha Gopalabhatla, Jhati Seelapureddy, Cindy (Xiangjia) Li

Arizona State University

The electric-assisted vat photopolymerization (e-VP) process offers a cutting-edge approach to fabricating bioinspired multiscale structures with controllable surface roughness, ranging from nanoscale to microscale textures. Utilizing optimized video projection and optical field modulation, e-VP combines high-speed, cost-effective additive manufacturing with precise nanofiller alignment in photocurable nanocomposites. This alignment is critical for tailoring surface textures, enhancing mechanical properties, and optimizing electrical conductivity—key factors for advanced material performance. By organizing nanofillers into defined patterns, e-VP replicates intricate nano-textures on microscale structures, improving durability and functional properties. However, monitoring nanofiller alignment during the process is challenging due to constraints in direct visualization, as the 3D printing platform is positioned above the resin tank. To overcome this limitation, this study integrates a machine learning system to monitor and optimize nanofiller alignment in real-time during the e-VP process. Using deep learning and anomaly detection, video data is analyzed to identify periods of stable and uniform alignment. Convolutional Neural Networks (CNNs) extract essential features from video frames, followed by Principal Component Analysis (PCA) for dimensionality reduction, ensuring computational efficiency. Anomaly detection methods, such as Hotelling’s T-squared analysis, identify optimal conditions for uniform nanofiller alignment. These insights inform voltage applications and process parameters, ensuring consistent material quality. Aligned nanofillers significantly enhance mechanical strength, surface roughness, and electrical properties, enabling high-performance applications in bioinspired coatings, wear-resistant materials, and electronic components. This integration of machine learning into e-VP represents a milestone in real-time quality control for additive manufacturing, aligning with the goals of precision engineering and sustainability. By advancing nanofiller alignment control, this research contributes to the development of complex, functional 3D-printed structures, highlighting its impact on materials engineering and advanced manufacturing.

2:00-2:20 p.m.: The Utilization of Sulfur Feedstocks and Organic Comonomers for the Development of Infrared Transparent Plastic Optics

Katie Martin*, Jeffery Pyun

The University of Arizona

The inverse vulcanization of elemental sulfur (S8) has been widely explored in efforts to improve material properties and expand viable applications via tuning of monomer structure, sulfur amount, and integration into fabrication methods for optical imaging and device applications. Sulfur based polymers exhibit enhanced infrared transparency, high refractive index, and retain the appropriate thermomechanical properties necessary for the fabrication of optical components for a variety of applications. Plastic optical components are desirable for infrared detection devices due to their low-cost, light weight, and tunability, however, the strong C-H and C-C absorption in the infrared region makes most polymers inappropriate for infrared applications. Depending on monomer composition, sulfur weight percent, and processing technique, each polymer system requires optimization for the intended application. In this talk we will discuss recent developments in the fabrication, characterization, and application of sulfur based infrared transparent polymers in efforts to further expand applications beyond the infrared region.

2:20-2:40 p.m.: Monitoring Bulk Photopolymerization Kinetics Using in-situ NMR Spectroscopy

Luis Jessen*, Kameron Hansen, Tanner Grover, Allan Guymon

The University of Iowa

The ability to precisely measure photopolymerization kinetics is paramount to controlling curing characteristics and material properties in photocurable systems. In this work, in-situ NMR spectroscopy was used to monitor bulk photopolymerization reactions to measure kinetic quantities such as relative rate parameters and ultimate monomer conversion. A 395 nm LED light source was used to initiate the polymerization of hexyl acrylate by directing light into the spectrometer to the sample using a fiber optic cable. The disappearance of the vinylic proton signal was quantified to obtain conversion profiles throughout the duration of the polymerization. Moreover, monitoring the disappearance of vinylic carbons showed strong agreement between 1H- and 13C-spectra. By varying the light intensity, the linear relationship between the relative rate parameter (kp’) and the square root dependence on the light intensity predicted by the steady state assumption, was confirmed. Furthermore, the polymerization of high-Tg monomeric species including N,N-dimethylacrylamide (AAm) and isobornyl methacrylate (IBOMA) revealed a need for high chain mobility of forming polymer chains to obtain processable signal late into the polymerization. By observing kinetic data of simple photopolymer systems, this work demonstrates the utility of in situ NMR photopolymerization as a complementary technique to conventional real-time Fourier-transform infrared spectroscopy (RT-FTIR) for the kinetic monitoring of photopolymer materials.

2:40-3:00 p.m.: Construction of an in silico EI Mass-Spectral Library for Polymeric Material Analysis using Pyrolysis-GC/MS and Machine Learning

Bryan Katzenmeyer*, Masaaki Ubukata, Ph. D., Ayumi Kubo, Azusa Kubota

JEOL

Pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) is an analytical method used to analyze nonvolatile samples, producing mass spectral information about their internal structures. This technique involves rapidly heating samples in an inert environment to generate pyrolyzates, which are then injected into a GC/MS system for subsequent separation and mass detection. A common challenge in polymer analysis is that many pyrolyzates are not found in commercially available electron ionization (EI) mass-spectral libraries, complicating their identification. To address this, we developed a virtual mass-spectral library by combining computational pyrolysis of polymers with machine learning to predict EI mass spectra from structural formulas. An acrylic resin was analyzed using gas chromatography high-resolution time-of-flight mass spectrometry (GC-HRTOFMS), where EI and field ionization (FI) techniques were utilized to produce mass spectral fragment ions and intact molecular ions to confirm molecular formula determination, respectively. Data were processed through peak deconvolution and alignment. Initial library searches revealed that while some monomers and dimers matched literature reports, many dimers and trimers could not be confirmed. We then conducted computational pyrolysis on 60 representative polymers, producing 10 million unregistered in silico pyrolyzates. The mass spectra were predicted and added to the virtual library, leading to the successful identification of previously unregistered thermal decomposition products from the acrylic resin. This novel approach allows for an efficient and accurate qualitative analysis of pyrolyzates derived from polymers using an in silico MS library developed using machine learning.

3:00-3:20 p.m.: Directing network degradability using wavelength-selective thiol-acrylate photopolymerization

Saleh Alfarhan*, Jared Nettles, Kailong Jin

Arizona State University

Wavelength-selective photopolymerization employs light at controlled wavelengths to trigger orthogonal photochemical reactions to fabricate multimaterials with unique combinations of building blocks and material properties. Prior wavelength-selective photopolymerization studies mainly focused on modulating the thermomechanical properties of the resulting multimaterials, which are often permanently crosslinked, non-degradable polymer networks. Here, we combine wavelength-selective photopolymerization with dynamic covalent chemistry to fabricate multimaterials with programmable, stimuli-responsive degradability in selected regions. Specifically, this study employs a thiol-acrylate photoresin comprising both wavelength-selective photoinitiators/photosensitizers and dynamic disulfide bonds. Green light irradiation triggers photobase generators to catalyze the thiol-acrylate Michael addition reactions, forming a step-growth polymer network with dynamic disulfide bond-based crosslinks. This green light-cured network can subsequently undergo degradation/decrosslinking by reacting with excess reactive thiols through thiol-disulfide exchange reactions. Meanwhile, UV light irradiation cleaves radical photoinitiators and thus promotes both radical-mediated acrylate homopolymerization and thiol-acrylate addition reactions, forming a permanently crosslinked chain-growth network that cannot be degraded. Promisingly, this thiol-acrylate photoresin can undergo orthogonal wavelength-selective photopolymerization under patterned green- and UV-light irradiation to form crosslinked multimaterials with pre-designed degradable regions, which can be selectively removed to reveal the underlying photomasks’ patterns. Overall, the chemistry demonstrated herein can be used to fabricate complex patterns and hierarchical structures, holding promise for applications ranging from photolithography to 3D printing.

3:20-3:40 p.m.: Blocky Polyethylene-Polycyclooctene Copolymers via Tandem ROMP/Hydrogenation

Minh Nhat Pham*, Caitlin Sample

Arizona State University

Polyethylene (PE) is one of the most produced plastics worldwide due to its remarkable mechanical properties. Incorporating PE into block copolymers to access unique self-assembly morphologies will result in unprecedented properties and applications of PE. Despite numerous efforts that have been made, the synthesis of PE block copolymers remains challenging due to the low reactivity of PE olefin terminal groups, multiple steps required, and limited choices of monomers. As a result, this restrains the number of available topologies and functionalities of PE block copolymers, especially multiblock copolymers of PE and unsaturated blocks are rarely reported. Here we present an efficient method of synthesizing blocky copolymers of PE and polycyclooctene (PCOE), blocky PE-co-PCOE, via tandem ring-opening metathesis polymerization (ROMP) and solid-state hydrogenation. Amorphous domains of PCOE were selectively hydrogenated to form PE blocks while PCOE crystallites were reserved as PCOE blocks. The fraction of the PE block is tunable through precisely controlling PCOE crystallization. The coexistence of crystallizable blocks of PE and PCOE was confirmed by differential scanning calorimetry and wide-angle X-ray diffraction. Unsaturated bonds of PCOE blocks allow further functionalization to introduce new moieties to blocky PE-co-PCOE, thereby expanding the library of PE block copolymers. This work demonstrates a new route to PE block copolymers, providing new opportunities for novel properties and high-performance applications.

3:40-4:00 p.m.: Digital Light Processing Printing of Hydrogel Based on Rapid Diels-Alder Click Chemistry

Takashi Taneko*, Sophia J. Bailey, Ronnie V. Garcia, Alison Chau, Angela A. Pitenis, Sijia Huang, Bryan D. Moran, Craig J. Hawker, Javier Read de Alaniz

University of California, Santa Barbara

The potential of 3D printing technologies, particularly in the biomedical field, is being significantly enhanced by innovations in hydrogel chemistry combined with digital light processing (DLP) strategies. DLP offers unique advantages, especially for producing complex structures like cell-laden tissues. However, traditional DLP techniques predominantly utilize radical photopolymerization of acrylate monomers, which can pose challenges for biological applications where the generation of radicals can adversely affect cell viability and alter proteins through unintended side reactions. To address these limitations, we have explored Diels–Alder (DA) cycloadditions due to their high selectivity and compatibility with biological systems. Diels–Alder (DA) cycloadditions are preeminent click reactions, unlike other common click chemistries that rely on toxic additives. Inspired by the high reactivity of cyclopentadiene (Cp) for DA click reactions, we have recently reported the development of photo-gated Cp derivatives that enable efficient bioconjugation and control of polymer click reactions without the need for radicals. Herein, we utilized this photo-gated Cp strategy for the development of novel photo-resins for DLP printing of hydrogel materials that are formed by rapid gelation via the DA click reaction between Cp and maleimide. As a result, the photo-resin rapidly formed hydrogel networks on irradiation with light, through an additive and radical-free step-growth gelation process. Photo-rheology studies on the gelation of the resin revealed that the resin has an efficient photo-curability. Additionally, we have shown that the resin is suitable for post-functionalization of the 3D-printed hydrogels, showcasing the potential of photo-gated click chemistry for accessing next-generation 3D-printed materials. This development paves the way for next-generation 3D-printed biomaterials that are not only effective for various applications but also safe for biological systems, ultimately enhancing the functionality and integration of printed tissues and devices in the biomedical landscape.

9:00-9:20 a.m.: Functional Polymeric ROMP-Boranes with Tunable Chemistry

Lakshita Anad*

Rutgers University

‘ROMP-Boranes’,1 boron-functionalized polymers that are prepared by facile ring-opening metathesis polymerization, are studied as a novel platform for supporting both Classical Lewis Pairs (CLPs) and Frustrated Lewis Pairs (FLPs). The dual functionality is attractive for applications in advanced material science and green chemistry. The strategic integration of ROMP-Boranes with functional organic chromophores leads to the formation of CLPs as robust complexes that exhibit interesting photophysical properties and hold promise for applications in organic light-emitting diodes (OLEDs) and (photo)catalysis. Simultaneously, FLP-functionalized ROMP-Boranes are pursued in small molecule activation for sustainable chemical transformations. This dual approach not only expands the versatility of ROMP-Boranes but also highlights their potential in driving future technological and environmental advancements.

9:20-9:40 a.m.: Bioinspired Recyclable Polymers for Rapid and Selective Heavy Metal Removal from Contaminated Water

Sungjin Jeon*, Teron Haynie, Samuel Chung, Cassandra E. Callmann

University of Texas at Austin

As industrial society advances, the demand for effective water remediation technologies becomes increasingly critical, especially to address heavy metal contamination. Heavy metals such as lead (Pb), cadmium (Cd), and nickel (Ni) pose serious environmental and health risks, even at low concentrations, making their removal from water sources essential. Traditional remediation methods often face limitations, including low removal efficiency, high energy consumption, and the generation of chemical sludge.
To address these challenges, we developed a bio-inspired, recyclable polymer system that efficiently captures and releases heavy metals. Using ring-opening metathesis polymerization (ROMP), we synthesized amphiphilic polymers with glucuronate-functionalized side chains, enabling selective binding of heavy metal cations. In water samples containing over 550 ppb of heavy metal ions, these polymers rapidly formed filterable precipitates, reducing metal concentrations to below 1.5 ppb within 3 minutes. This rapid capture is confirmed using inductively coupled plasma mass spectrometry (ICP-MS), demonstrating the system's ability to meet stringent safety standards.
The polymers' pH-responsive behavior allows for the reversible capture and release of heavy metals. Upon acidification, the glucuronate groups become protonated, releasing the bound metal ions and redissolving the polymer, enabling efficient reuse across multiple cycles without significant loss in binding capacity. This feature addresses key drawbacks of traditional methods by minimizing energy consumption and reducing chemical waste.
Our bio-inspired polymer system provides a sustainable and effective solution for heavy metal remediation, offering potential for large-scale applications in water purification. By combining high selectivity, rapid action, and reusability, this system represents a promising advance in the field of environmental cleanup, contributing to safer water resources in industrial and natural settings.

9:40-10:00 a.m.: Elucidating the Nanoscale Interactions between Invertible Polymeric Micellar Assemblies and Biopolymer Cargo

Mariia Usiichuk*, Zoe Armstrong, Zhongyu Yang, Andriy Voronov

North Dakota State University

Invertible micellar assemblies (IMAs) from amphiphilic invertible polymers show great potential for solubilizing and delivering otherwise insoluble compounds, particularly therapeutic polypeptides, in an aqueous medium. Although fundamental aspects like phase transitions and structural dynamics of IMAs have been previously studied, understanding the micellar interior morphology (local crowding) and solvent accessibility (local polarity) upon the incorporation of biomacromolecules and/or environmental (polarity) changes, as well as the location of cargoes upon loading into IMAs, remains limited. To gain deeper insights into the interactions between IMAs and biomacromolecular cargo, a combination of site-directed spin labeling (SDSL) and Electron Paramagnetic Resonance (EPR) spectroscopy is used.
This research investigates the interactions between IMAs from amphiphilic invertible polymer synthesized from polyethylene glycol, Mn =600 g/mol, and polytetrahydrofuran, Mn = 650 g/mol (PEG600-PTHF650) and cargo macromolecules synthesized from polyethylene glycol and polycaprolactone of varying molecular weight (PEG-PCL). The chemical structure, surface activity, and micellar size of both copolymers were characterized using ¹H NMR spectroscopy, FTIR spectroscopy, surface tension, pyrene solubilization, and DLS. The latter technique indicates an increase in IMAs size upon incorporating PEG-PCL macromolecules. Furthermore, a combined SDSL-EPR approach for detailed investigation of interactions between IMAs from PEG600-PTHF650 and PEG-PCL is currently being applied.

10:00-10:20 a.m.: Immunomodulatory poly(alpha ketoglutarate) microparticles to enhance bone repair

Margaret Dugoni*, E Mahadevan, S Bogner, A Esrafili, S Pathak, MMC Sekhar Jaggarapu, J Westendorf, A Acharya, J Holloway

Bone metabolism is an important research area that remains largely understudied, especially given the $5 billion in annual bone graft implantations. Bone morphogenetic proteins (BMPs) are growth factors that are clinically approved to promote bone repair; however, high supraphysiological concentrations required for the sustained, desired balance between osteogenesis/inflammatory signaling, costs, and adverse effects have prevented the full impact of BMP based therapies. We have designed novel small molecule metabolite microparticles of polyesters of alpha-ketoglutarate (paKG) encapsulated in hyaluronic acid hydrogels to co-deliver BMP2 and paKG through cell-mediated proteolytic degradation. aKG in its monomer form has been shown to promote bone growth and simultaneously inhibit bone resorption. Additionally, PaKGs are highly tunable, and hydrolytically degrade, so, as the hydrogel degrades there will be a controlled, sustained release of PaKG and BMP2 to promote bone repair for the full cycle of bone healing. paKG microparticles were synthesized through double emulsion. Maleimide modified hyaluronic acid (MaHA) was synthesized and paKG microparticles were successfully encapsulated within MaHA hydrogels. paKG association and internalization with human mesenchymal stem cells was confirmed through confocal imaging of fluorescently tagged microparticles. Additionally, preliminary results suggest paKG delivery to hMSCs in osteogenic media impacts cell number and mitochondrial capacity. Ongoing research is more fully investigating the impact of paKG delivery on osteoblast and osteoclast activity. We expect paKG delivery will enhance osteoblast differentiation and bone formation, while inhibiting osteoclast differentiation and bone resorption. Furthermore, we expect BMP2 delivery in combination with paKG delivery using the MaHA hydrogel system will enable increased osteogenesis at lower BMP2 doses. We have previously demonstrated BMP2 delivery can be tuned by using proteolytically-degradable crosslinkers and controlling MaHA crosslink density. The approach of sustained metabolic delivery can be generalized and may enable researchers to employ immunomodulation to augment healing in other tissue engineering applications.

2:00-2:20 p.m.: Robust Self-Healing Adhesives Based on Dynamic Urethane Exchange Reactions

Lillian Fesenthal*, Subeen Kim, William R. Dichtel

Northwestern University

Structural adhesives play a crucial role in everyday life to bond joints in automotive, textile, construction, household, and other settings. Hot melt adhesives, comprised of thermoplastic polymers, provide ease of handling and reprocessability but lack the high tensile strength needed for structural bonding. Conversely, thermoset adhesives are typically cured directly on the adherends, providing enhanced strength. However, due to their crosslinked structure, recycling and reuse of thermoset adhesives are not possible. Covalent adaptable networks (CANs) bridge the gap in reprocessing between thermoplastics and thermosets by incorporating dynamic crosslinks. Polyurethanes (PUs) are one of the top produced thermoset polymers worldwide, with over 18 million tons being manufactured in 2019 and 230,000 tons utilized as adhesives or sealants. Thermoset PUs have been successfully reprocessed as CANs by catalyzing carbamate exchange. Here we extend bond exchange beyond the internal network crosslinks to create a dynamic urethane adhesive. Interfacing PU CANs to substrates with nucleophilic functional groups creates adhesives capable of reversible transcarbamoylation with the substrate, which has not been demonstrated previously by CAN adhesives. Two types of thermoset PU films were synthesized, one containing the green carbamate exchange catalyst Zr(tmhd)4 and the other containing no catalyst. Although otherwise identical in chemical and network properties, as indicated by FT-IR spectroscopy and dynamic mechanical thermal analysis (DMTA), the film containing catalyst showed dynamic bond exchange behavior through stress relaxation analysis. When evaluated as an adhesive, the CAN film exhibited self-healing properties and retained its adhesive strength for five cycles, which is attributed to reversible covalent bonding to the glass substrate. This work expands industrially relevant CANs to structural adhesives and demonstrates their potential value in an application that presently employs PUs as single-use materials.

2:20-2:40 p.m.: Rapidly hydrolyzable polylactide containing salicylate additives

Eric Rachita*, Taylor Larison, Marc Hillmyer, Christopher Ellison

University of Minnesota

Polylactide (PLA) biodegradability is limited to industrial composting conditions where high temperature, moisture content, and microbial concentration degrades the material in several months. Strategies to enhance PLA degradability could alleviate plastic bioaccumulation and provide opportunity for at-home composting where conditions are not as stringently controlled. Towards that end, salicylate-containing small molecules based on naturally abundant salicylic acid (SA) were prepared to investigate their effectiveness in accelerating PLA degradation. Blends of initially amorphous PLA with low levels of SA, disalicylide (DS), or oligosalicylate (OS) were prepared using scalable melt processing techniques. The glass transition temperature, tensile properties, and shelf-life stability of the salicylate-containing blends were nearly identical to neat PLA. The inclusion of salicylate additives accelerated sample mass loss in artificial seawater at 50 °C by up to a factor of three as compared to neat PLA. The rate of molar-mass loss in 1 wt.% salicylate-containing blends was up to twice as fast as the rate of neat PLA. The accelerated hydrolysis observed in the salicylate-containing blends outpaces degradation-induced PLA crystallization which serves to slow sample mass loss over time in neat PLA. We conclude that a low concentration of carboxylic acid groups from salicylate-containing compounds is sufficient to promote the autocatalytic effect and enhance PLA degradability without sacrificing material performance.

2:40-3:00 p.m.: Understanding the Tradeoff Between Reprocessability and Mechanical Strength in Silicones

Anisha Sharma*, Broderick Lewis, Ben Hafner, Kenneth Shull

Northwestern University

Silicones are ubiquitous materials in everyday life, harboring advantageous properties such as strong thermal stability and high strain to failure. However, many silicones lack good toughness and are unable to be recycled due to their crosslinked nature. Covalent adaptable networks (CANs) contain dynamic bonds which, under an external stimulus such as light or heat, allow for traditionally non-reprocessable polymers such as thermosets and crosslinked elastomers to be reprocessed. Additionally, these unique chemistries can help improve toughening and other properties of the material, creating a more resilient polymer overall. This project aims to develop a reprocessable silicone by reacting a dynamic disulfide-containing amine cross linker (DTDA) with an epoxide-terminated polyphenylmethylsiloxane (EPS). The topology of the system is altered by integrating an octafunctional polyhedral organosilsesquioxane (POSS) resin in varying concentrations. The addition of POSS adds permanent crosslinks to the polymer, affecting the percolation threshold - the point at which a permanent backbone is formed which inhibits reprocessing of the polymer - and the overall properties of the system, such as increases in tensile strength and modulus. Dynamic mechanical analysis, differential scanning calorimetry, tensile testing, and pure shear fracture experiments are employed to understand where the best tradeoff between mechanical strength and reprocessability lies.

3:00-3:20 p.m.:  Alternative poly (ester acetal)s as degradable replacement for commodity plastics

Roberto Venta*, Dr Colleen Scott

Mississippi State University

Plastic waste has become a significant problem in recent years due to its adverse environmental impact. The main challenge is the high production volume of commodity plastics and the lack of degradation or proper disposal, which leads to massive accumulation in landfills, oceans, and forests. To address this issue, there is a great demand for developing polymers that possess similar thermal and mechanical properties to commodity plastics but degrade appreciably to protect our environment. Here, we designed and synthesized a series of bio-based degradable copoly (ester acetal)s derived from vanillin. The biobased vanillin core offers the potential for similar mechanical and thermal properties to some commodity polymers, while the labile acetal group incorporated into the backbone provides degradability to the polymers. We described the synthesis of some homopolymers and copolymers, which were characterized using 1H NMR, DSC, and GPC. The results show current Tg values between 10-38 oC at a molecular weight (Mw) of 15 kDa and a 1.2 degree polymerization index (PDI). Additionally, the 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) catalyst gave higher performing polymers compared to commercial Lewis-Acid metal catalysts.

3:20-3:40 p.m.: Depolymerizable and recyclable luminescent polymers with high light-emitting efficiencies

Yukun Wu*, Wei Liu, Sihong Wang, Jie Xu, Jianguo Mei

Purdue University, Argonne National Laboratory

Luminescent polymers are of great interest in a number of photonic technologies, including electroluminescence, bioimaging, medical diagnosis, bio-stimulation and security signage. Incorporating depolymerizability and recyclability into luminescent polymers is pivotal for promoting their sustainability and minimizing their environmental impacts at the end of the product lifecycle, but existing strategies often compromise the light-emitting efficiencies. Here we develop a strategy that utilizes cleavable moiety to create depolymerizable and recyclable thermally activated delayed fluorescence (TADF) polymers without compromising their high light-emitting efficiencies. The electroluminescent devices based on the TADF polymers achieved a high external quantum efficiency of up to 15.1 %. The TADF polymers can be depolymerized under either mild acidic or heating conditions, with precise control of the kinetics, and the obtained pure monomers can potentially be isolated and repolymerized for subsequent life applications. This work promotes the end-of-life environmental friendliness and circularity of luminescent materials, paving the way to a sustainable photonic industry.

3:40-4:00 p.m: Withdrawn

9:00-9:20 a.m.: Functionalized Fabric Matrix for Enhanced Efficiency in Direct Air Capture

Deepak Narayana Murthy Akundi*, Marlene A. Velazco Medel, Kacie Niimoto, Matthew D. Green

Arizona State University

Since the Industrial Revolution, carbon dioxide emissions have increased at alarming rates, necessitating urgent action to both reduce current emissions and remove existing CO2 from the atmosphere. In response, numerous technologies have been developed, with Direct Air Capture (DAC) emerging as a promising solution.
Sorbents play a crucial role in DAC and are categorized based on their sorption mechanisms. Amine-based sorbents are among the most used, relying on temperature changes for adsorption and desorption. Although these sorbents offer high capture capacities, they have the drawback of requiring substantial external energy.
To address these high energy demands and reduce operational costs, Dr. Klaus Lackner proposed a novel sorption technique known as the "moisture swing." In this approach, CO2 capture is driven by changes in humidity rather than temperature, which significantly lowers energy requirements. Moisture-swing sorbents are typically strong, basic ion-exchange resins containing quaternary ammonium ions (NR4+) with carbonate, bicarbonate, and hydroxide counter-ions. The relative abundance of these counter-ions depends on the moisture level and COâ‚‚ load on the ionic sorbent.
However, because moisture-swing sorbents are highly hydrophilic, they face challenges in high-humidity conditions. Even slight increases in humidity over time can dissolve the polymer, rendering the sorbent unusable. To address this, crosslinkers can be introduced to create a non-soluble polymeric network. Yet, studies indicate that even crosslinked networks can retain excess water, forming hydrogels that hinder gas diffusion and reduce efficiency.
This research seeks to enhance moisture-swing DAC by creating a matrix with immobilized sorption sites on a hydrophobic fabric support with moderate crosslinking. The hydrophobic fabric minimizes water uptake, enabling faster drying and enhancing the sorption-desorption cycle. This approach increases surface area, improves thermo-mechanical stability, and enhances gas permeation and diffusion, ultimately aiming to improve moisture swing sorbents and DAC efficiency.

9:20-9:40 a.m.: Experimentation for characterizing sorbents used in Direct Air Capture of CO2

Mitesh Patil*, Matthew Green, Klaus Lackner

Arizona State University

Direct Air Capture (DAC) of CO2 is an important tool to combat rising atmospheric COâ‚‚ levels that drive global warming. DAC systems include Moisture Swing (MS) and Temperature Swing (TS) sorbents. MS induces desorption in certain sorbents by lowering their affinity to CO2 with water, which makes it possible to release CO2 in an isothermal swing. By contrast, TS sorbents release CO2 through heating. Heat can be provided via steam condensation or steam adsorption on the sorbent.
To improve DAC efficiency and study desorption with low pressure steam, we designed a bench-scale apparatus that injects water vapor into a sorbent chamber and analyses the product stream. The exothermic effect of water adsorption can result in sorbent temperature higher than in the water source. With real time measurements of temperatures and pressures in the water reservoir, the sorbent chamber and downstream where the product gas mixes a controlled flow of sweep gas nitrogen that carries the product through a vacuum compressor to gas analysis makes it possible to measure CO2 flows and H2O flows from the reaction chamber while simultaneously performing calorimetry. This one-of-a-kind apparatus provides insights into sorbent behaviour by capturing temperature rises during water adsorption and COâ‚‚ release under vacuum conditions. We have demonstrated the autothermal effect and shown that we can quantitatively unload the sorbent. By characterizing sorbents under varied COâ‚‚ and Hâ‚‚O loading states, we can optimize DAC performance and material stability, helping to enhance the scalability of DAC systems. This study provides essential data for the improvement of sorbent materials and operational efficiency in DAC applications.

9:40-10:00 a.m.: Biocompatible Polymers for COâ‚‚ Capture and Delivery in Cyanobacterial Cultivation

Marlene Velazco Medel*, Sunil Tiwari, Shuqin Li, Justin Flory, Wim Vermaas, Matthew D. Green

Arizona State University

As the global need for sustainable carbon capture technologies grows, Direct Air Capture (DAC) has emerged as a viable solution. This study introduces a novel polymer-based approach to capture COâ‚‚ via moisture-swing (MS) sorbents, designed specifically for compatibility with cyanobacterial cultivation. We developed hyper-crosslinked polymers with quaternary ammonium (QA) functional groups to enable efficient COâ‚‚ capture and release, tailored for biocompatibility with Synechocystis sp. PCC 6803. The polymers demonstrated significant COâ‚‚ desorption in aqueous media, particularly in CAPS-buffered solutions (pH 10.5), supporting sustained photosynthetic growth. In 12-day cultivation trials, polymers with six-carbon and xylene spacers released up to 0.54 mmol COâ‚‚/g, maintaining low cytotoxicity and enhancing bioproductivity. Synechocystis cultures exposed to these polymers exhibited growth rates comparable to or exceeding traditional bicarbonate supplementation, highlighting their dual role in DAC and biofuel production. Additionally, polymer stability in alkaline conditions ensured reusability, reducing environmental impact. This approach presents a scalable pathway to carbon-negative biofuel and bioproduct generation by directly integrating DAC COâ‚‚ into photosynthetic cultivation, underscoring the potential of biocompatible MS sorbents for future carbon utilization in biotechnology.

10:20-10:40a.m.: A study on the epoxy-based polymer nanocomposites and the role of the curing agent

Romina Keshavarz*, Matthew Green

Arizona State University

Stimuli-responsive polymers are a class of polymers that can be used as sensors because they respond to a variety of internal and external stimuli, such as mechanical force. Mechano-responsive polymers are useful for detecting damage upon the applied mechanical force. In our system, this mechanical force is transduced into optical signals using nanomaterials, including core-shell quantum dots and fluorescent dye-modified carbon nanotubes, which leads to fluorescence activation of nanomaterials after deformation occurs. Moreover, the dispersion of nanomaterials within epoxy resins has been a challenging research topic. To improve the dispersion of nanomaterials, we developed new nanocomposites with well-dispersed nanomaterials cured with different aliphatic and aromatic diamines. In the literature, several researchers have investigated the functionalization of carbon nanotubes to enhance their dispersion within the matrix. In this study, we will focus on how changes in the curing agents’ structure influence the dispersion of these nanomaterials, which in turn impacts the damage detection sensitivity and the mechanical properties of the composite.

10:40-11:00 a.m.: Experimental Study on CO2-Sensitive Gel-Type Sealant for sealing Leaky Carbon

Ishtiaque Anwar*, Meng Meng, J. William Carey, Robert Gilbertson, Nevan Himmelberg, Weicheng Zhang, Emily Tao, and Rajesh Nair

Los Alamos National Laboratory

Potential upward leakage of CO2 and reservoir fluid within a leaky sequestration well poses potential environmental and economic risks. This research investigates recently developed techniques for wellbore remediation in the challenging environments posed by the presence of CO2. A comprehensive experimental investigation was conducted on the properties and behavior of a modified CO2-sensitive methyl methacrylate-based gel under varied conditions to understand its application in remediating carbon sequestration site. Multiple experimental measurements are carried out. The extent of the gel's expansion as a function of time was measured using laser profilometry under different states and conditions. Rheological measurements of both unreacted and reacted sealants of different concentrations were recorded to shed light on the penetrability of the sealant and yield stress of the sealant (CO2-swelled gel). Thermogravimetric analysis and thermo-stability measurements were employed to understand the sealant’s behavior at higher temperatures. CO2 flow tests were also undertaken at simulated downhole condition to evaluate the sealing behavior of injected sealant. The interaction of the gel-type sealant with CO2 was further analyzed using isotope-ratio mass spectrometry (IRMS). The behavior of the gel-type sealant depends on multiple factors - exposure duration, gel concentration, pH, and temperature. Isolated pieces of gel can swell up to about 20 times of its original volume upon exposure to CO2 and moisture, which makes it a good candidate to fill leakage pathways. The sealant maintains its flowability at a relatively higher pH with lower viscosity. We observed that the dynamic viscosity of the sealant significantly increases when exposed to CO2 and water, making the gel thicker (lower pH), signifying a greater resistance to flow. A Hershel-Bulkley fit of rheological data indicates an elevated yield stress of the reacted sealant, which seals leakage according to the literature. The viscosity of the reacted gel-type sealant increases with the gel concentration. The sealant can maintain its structural integrity and performance at elevated temperatures (up to 140°C) and CO2 pressure (about 1550 psi). Flow tests indicate that the sealant reacts with CO2 over time, leading to a reduction in permeability, and at adequate concentration, it completely seals the leak. Furthermore, IRMS with SEM show that the reacted sealant can trap a substantial amount of CO2 that can protect the wellbore cement from mechanical degradation due to carbonation. These experimental results demonstrate that methyl methacrylate-based CO2-sensitive gel not only capable of sealing wellbore flaws upon exposure to leaking CO2, but also shields wellbore cement from further carbonation, offering a promising solution to the well remediation.

11:00-11:20 a.m.: Sequestration Wellbores

Zachary Baierl*, Austin Mills, Andrew Ko, Kathryn Daltorio, Gary Wnek

Case Western Reserve Univeristy

Vulcanized rubbers are frequently selected for use in applications requiring the combination of energy dissipation, shape recovery and property retention. With a wide variety of chemistries, molecular weights, and crosslinking densities, these materials can serve as a platform for many products. These products can be further fine-tuned via additional processing, such as blending of inorganic or organic components, thermoforming complex structural shapes, and surface modifications. However, these materials are fundamentally thermosets in that once formed and crosslinked, they cannot be reprocessed via traditional means. Isobutylene isoprene rubber (IIR) products such as tires can be downcycled after they are mechanically ground and mixed with adhesives and fillers into asphalt filler, tracks, playgrounds, and small consumer products. The well-established rubber industry, born from the vulcanization of natural rubber (NR) in the mid-1800s and transformed in the 1940s with the discovery of synthetic rubbers such as IIR, can significantly benefit from some sustainability innovations.
One potential innovation is the utilization of unvulcanized rubbers as part of a layered composite structure with highly compatible Thermoplastic elastomers (TPEs). These TPEs are physically crosslinked, which provides rigidity and a return force while confining the unvulcanized layers. This composite structure is entirely thermoplastic, meaning it can be separated and reprocessed. We have previously reported the mechanical response of stretching viscoelastic mismatching bilayers of these systems (DOI: 10.1039/D3SM01004J). The current work explores the response of trilayer structures with a core of unvulcanized rubber material to mechanical stimuli. In addition to evaluating the in-plane tensile mechanical response, a significant effort has been made to explore the energy dissipation capabilities of these films. A custom ball drop apparatus utilizing a high-speed camera was fabricated for this investigation. Ultimately, an attractive proposal exists in widely utilizing these more sustainable multilayer composites.

11:20-11:40 a.m.: Fundamental Investigations into Ceramic Yield and Composition of Preceramic Polyoganodecaboranes and Polyorganodecaborane Grafted Nanoparticles

Benjamin Stovall*, Kavindi Sabaratne, Robert Hickey

Pennsylvania State University

Boron carbide (B4C) is a ceramic of considerable interest to researchers due to its high hardness, melting point, excellent thermal stability, low density, and chemical inertness, making it a valuable material for engineering applications. Decaborane-functionalized preceramic polymers (PCPs) from ring-opening metathesis polymerization (ROMP) are excellent single-source precursors of boron carbide. However, there have been few reports since the early 2000s, and there is much to investigate regarding the improvement of synthetic conditions, molecular weight, and ceramic yield. Poly(cyclooctenyldecaborane) (PCD) is explored to understand the consequences of molecular weight and crosslinking on B4C ceramic yield, which is not only important fundamentally but also practically to inform processing conditions and material design for use in such applications as additive manufacturing. ROMP of the cyclooctenyldecaborane monomer enables controllable molecular weight and produces a series of polymers with molecular weights up to 35 kg/mol and dispersities (Ð) in the range of 1.3-1.6. Bulk pyrolysis coupled with techniques including thermogravimetric analysis and x-ray diffraction facilitates the characterization of ceramic yield and composition. Furthermore, the addition of ceramic or metallic particles can improve ceramic yields and reduce shrinkage of PCPs during pyrolysis. Surface-initiated ROMP (SI-ROMP) provides synthetic opportunities to generate polymer brushes on particle surfaces and allows for precise control over polymer graft density and molecular weight. SI-ROMP affords a facile strategy for grafting different classes of PCPS and is exploited to give silica nanoparticles grafted with polyorganodecaboranes. This method provides access to modular preceramic precursors with varying final ceramic compositions and microstructure, expanding beyond the predominant silicon-based polymer systems.

11:40 a.m.-12:00 p.m.: Mechanophore-Functionalized Thermosets: Advancing Multifunctionality for Structural Applications and Sustainability

Xiangbang Zhao*, Chris Whitney(Coauthor); Jose Roman; Aditi Chattopadhyay; Lenore Dai

Arizona State University

As the demand for intelligent materials in structural applications continues to rise, multifunctional capabilities have become essential. Traditional approaches to achieving these features typically involve directly blending additives, which can compromise mechanical properties. This work introduces a novel strategy to integrate mechanochemistry-based functional moieties into thermoset polymer systems, specifically using highly adaptable shape memory polymer (SMP). Our approach involves chemically grafting a mechano-responsive molecule – mechanophore – along with an amine crosslinking agent to form an advanced crosslinked network that enhances multifunctional performance in polymer systems. Comprehensive characterization through dynamic mechanical analysis, tensile testing, and in situ, fluorescence monitoring confirms that this polymer design offers stress-responsive capabilities, enabling early-stage damage detection via fluorescence activation under mechanical loading through a reversible photocycloaddition process. Moreover, beyond early damage sensing, the material offers a photochemically aided healing mechanism, where UV light exposure re-dimerizes mechanophore units within the thermoset, reinforcing structural integrity. Including mechanophores further enhances the dynamic mechanical properties of the SMP thermoset while preserving its inherent shape memory behavior. This multifunctional thermoset development represents a significant advancement in intelligent materials. Its unique properties make it ideal for a range of applications, from high-performance structural materials to sustainability-oriented polymer systems. This versatility paves way for future research into the development of higher durability and longer life cycle materials with improved mechanical properties, spanning from polymers to polymer composite systems.

12:00-12:20 p.m.: Synthesis And Characterization of Polyurethane Coatings Derived from Palm Olein/Recycled PET Polyols for Metal Surface Protection

Addas Adamu*, Ado Ali Danbatta

Hussaini Adamu Federal Polytechnic

Polyols of palm olein/recycled PET were synthesized by first preparing pam olein alkyd resin and added in recycled PET in different percentages by glycolysis process. Characterization of the polyols were done by FTIR and OHV determination using standard method. Polyurethane coatings were prepared by dissolving the polyols in solvent mixture of cyclohexanone/THF (80:20) ratio and reacted with stoichiometric amount of 2,4-toluene diisocyanate (TDI) in the presence of a tin catalyst (DBTDL, 0.05 wt. %). Mild steel panels were then coated with the PU coating and cured at fume hood for 5 days at ambient temperature. To ensure complete curing, the panels were placed in an oven and left overnight at 50oC. The films were characterized by FTIR, physicochemical, thermal and anticorrosion properties. The FTIR proves the presence of polyurethane linkage and coatings exhibit good physicochemical, thermal and anticorrosion properties. Higher ratio of recycled PET incorporated in the polyols has yielded a better film property. Recycled PET waste has been proven to enhance the performance of the PU as anticorrosion coatings.

9:00-9:20 a.m.: Rapid and highly selective ion conduction via decoupling ion transport from polymer segmental relaxation in single-ion-conducting, polymer-blend electrolytes

Menying (Sara) Yang*, Thomas H. Epps, III

University of Delaware

The inherent trade-off between rapid polymer segmental relaxation and sufficient free lithium ion (Li+) is known to constrain conductivity enhancement and limit performance. To break this anticorrelation, we blended a glassy single-ion-conducting polymer, poly[lithium sulfonyl(trifluoromethane sulfonyl)imide methacrylate], with a flexible ion-conducting polymer, poly(oligo-oxyethylene methyl ether methacrylate), to decouple ion transport from polymer segmental dynamics. We connected the ion transport mechanism to the packing frustration of polymer chains and investigated composition-dependent thermodynamic and conductive properties via differential scanning calorimetry, electrochemical impedance spectroscopy, and dynamic mechanical analysis. High Li+ conductivities (~10-2 S/cm) with rapid transport mimicking inorganic superionic conductors were realized due to decoupled ion transport. Additionally, immobilized anion resulted in high Li+ selectivity (Li+ transference number = 0.9), electrochemical stability (4.7 V against Li+/Li), and limiting current density (1.8 mA/cm2, electrolyte thickness = 0.05 cm). These results suggest that polymer chain packing frustration can be exploited to achieve rapid and highly selective ion conduction in high-performing polymer electrolytes.

9:20-9:40 a.m.: PNIPAM-based Polymers with Selective Absorption for Polar Liquid from Non-Polar Liquid

Gahee Im*, Gibum Kwon

University of Kansas

Separating miscible liquids is an important step in various processes such as wastewater treatment, pharmaceutical engineering, petrochemical product refining, and the food and beverage industry. The current distillation method is limited due to its high energy consumption and lack of ability to separate azeotropes. Herein. we report a poly(n-isopropyl acrylamide) (PNIPAM)-based polymer that demonstrates selective absorption for ethanol from n-heptane. This was verified by refractive index measurements of the feed mixture and the retentate after absorption experiments. Furthermore, PNIPAM copolymerized with fluorinated acrylate (f-PNIPAM). F-PNIPAM exhibited more ethanol absorption which can be attributed to a lowered affinity to n-heptane. These results suggest the potential of the proposed material and mechanism to substitute the distillation method.

9:40-10:00 a.m.: Enabling bio-cathode with graphene coating via networking soy-protein and polydopamine for Li-S batteries

Ying Guo*, Chunhua Ying, Lulu Ren, Justin Zhong, Jin Liu, and Wei-Hong Zhong

Washington State University

The abundance and environmental friendliness in nature of sulfur (S) make Li-S batteries more attractive in addition to the high theoretical capacity (1675 mAh g−1) and energy density (2600 Wh kg−1) of the batteries. In this study, a bio-based S cathode with a graphene (Gr) coating, capable of effectively suppressing the shuttle effect of polysulfides, was enabled via networking soy protein (SP) and polydopamine (PDA) to form a functional bio-binder (SP-PDA). Dopamine self-polymerization in SP does not only generate the interpenetrated network for the bio-binder but also makes the denatured structure of SP with rich functional groups effective for trapping polysulfides. Meanwhile, the Gr coating with low impedance, high electronic and ionic conductivity on the cathode surface further significantly reduces polysulfide dissolution. Consequently, the Li-S batteries with the bio-cathode (SP-PDA@Gr) demonstrate excellent rate performance and long cycling capacity. In specific, under the current density of 0.5 A g-1 at 70 % (500 mAh g-1) capacity retention, the cycle life of the Li-S cell with SP-PDA@Gr cathode is 600 cycles, i.e.,100 times longer than that of the cell with PVDF binder. This study provides a sustainable strategy for enhancing the performance of Li-S batteries through networking natural protein to form functional bio-binder.

10:00-10:20 a.m.: Withdrawn

10:20-10:40 a.m.:  Time-Dependent Mechanical Enhancement of Polylactic Acid Through Biaxial Cold Rolling

Brandi Martz*, Tiffany Lee, Gary Wnek

Case Western Reserve University

Polylactic acid (PLA) is a renewably-sourced, biodegradable polyester known for its high mechanical strength, optical transparency, and good barrier properties. Despite its many benefits, widespread adoption is limited by PLA’s intrinsic brittleness. One way to address ductility concerns is through roll milling–a solid-state processing method that utilizes shear and compression to produce oriented workpieces of uniform thickness. Roll milling has been shown to increase ductility and mechanical strength in commodity polymers without the need for fillers or reinforcing fibers. The current work examines the time-dependent mechanical enhancement of biaxially oriented, low crystallinity PLA using roll milling at room temperature. In addition to low crystallinity PLA, the effects of annealing to induce moderate crystallinity after rolling are also being explored. Early findings reveal increased toughness, tensile strength, and 2% secant modulus with a strong dependency on the timeframe between rolling and mechanical testing. The effects of roll milling on impact strength and flexural properties are also being investigated. The results of this study aim to reduce the use of unsustainable, expensive, and complex fillers traditionally used to toughen PLA products. As global demand for more sustainable materials grows, roll milling presents an opportunity to expand the use of PLA in the packaging, medical, and consumer products industries.

10:40-11:00 a.m.: Engineering the Future of Soft Materials: 3D Printing Bottlebrush Siloxane-Based Elastomers

Kamyar Karimi Nikoo*, Jeffery Self

Arizona State University

This work introduces a novel approach to polymeric networks using a bottlebrush architecture to create super-soft, solvent-free materials. Poly(dimethylsiloxane) (PDMS) is well established for its biocompatibility, insulating properties, and thermal resilience. However, additive manufacturing of PDMS commonly presents challenges, primarily due to its high viscosity and suboptimal interlayer bonding strength. To address these limitations, our research is dedicated to formulating novel PDMS photoresins and optimizing their 3D printing. By prioritizing fast photocrosslinking and reduced ink viscosity, we aim to take advantage of high resolution and rapid prototyping capabilities of vat photopolymerization. In addition to material chemistry, the model design plays an important role in determining the mechanical properties of printed parts. Factors such as porosity and effective surface area can directly affect a printed part’s performance. 3D printing of super-soft, solvent-free materials that easily mimic the softness of biological tissues expands new applications in soft robotics, flexible electronics, tissue engineering, and implantable devices.

11:00-11:20 a.m.: Sulfur-based optical polymers: Sustainable approaches to visible and infrared imaging and photonics

Jake Molineux*, Jeffery Pyun

University of Arizona

The development of high sulfur content polymeric materials continues to be of interest due to the unique properties of these polymers as well as the utilization of waste sulfur from petroleum refining. Recent advances in polymer synthesis by Pyun et al. provides novel method of incorporating high sulfur content directly into polymers from elemental sulfur through inverse vulcanization, or from low-cost sulfur derivatives like sulfur monochloride with sulfenyl chloride inverse vulcanization. Both of these systems can be leveraged to make highly networked thermoset materials with high refractive index and high transmissivity in the visible and infrared spectral regions, but due to the intrinsic nature of thermosets, the forms of post-polymerization processing remain limited. The strong optical properties of these materials as measured with traditional spectroscopy provides motivation to directly evaluate material in an in-situ prototype imaging system or other optical or photonics devices. These materials further benefit from sulfur inclusion in the polymer backbone as this allows for chemical degradation by means inaccessible to carbon-based polymers. Herein we will discuss the design and synthesis of high sulfur content polymers from thiol-free feedstocks and the processing and fabrication methods that allow direct evaluation materials in prototype optical and photonics systems.

11:20-11:40 a.m.: Physical aging in additively manufactured PETG

Sierra Yost*, Jordan C. Smith, Christian Pester, Bryan D. Vogt

Pennsylvania State University

Material choices for materials extrusion additive manufacturing (MEX) have expanded tremendously in the past decade, but the figures of merit for performance tend to be associated with optimization of print parameters for a given plastic filament and printer to maximize some mechanical property, commonly elastic modulus. However, the properties of plastics can be altered over the lifetime of its use through physical and chemical aging. Here, we focus on elucidating how 3D printing impacts the physical aging of a common MEX filament, poly(ethylene terephthalate glycol) (PETG). PETG is a copolymer where ethylene glycol in common PET is replaced with cyclohexane dimethanol (CHDM). This copolymerization disrupts packing to reduce crystallinity and creates an easier-to-print amorphous polymer. However, the molar percentage of CHDM varies across commercial filaments that leads to alteration in the local dynamics of the chains. Lower CHDM content results in higher glass transition temperatures. In this study, three PETG filaments with CHDM contents of 17, 13, and 11 mol % were printed into ASTM D638 Type IV and Type V tensile bars and subjected to accelerated aging to examine how aging for years influences the mechanical response of 3D printed plastics. Aging led to stronger, but more brittle materials over approximately 1 year of ambient temperature aging for Type IV tensile bars, but the elongation at break tended to increase for printed Type V tensile bars. Additionally, non-monotonic changes in elastic modulus on aging is found for the PETG with high concentration of CHDM. These results illustrate the complexity in aging of MEX products where the rate and even directionality to the property change can be impacted by details of the print path and the exact filament selected, even when the plastic is nominally the same.

11:40 a.m.-12:00 p.m.: Hydrogel Encapsulated Living Soil Sensors: Towards Detecting Bioavailable Phosphorus and Beyond

Raj Mukkamala*, Oumeng Zhang, Reinaldo E. Alcalde, Ting-Yu Cheng, Elin M. Larsson, Dianne K. Newman, and Julia A. Kornfield

California Institute of Technology

Phosphorus, a vital nutrient for crop growth, often becomes inaccessible to plants due to fixation in the soil, leading to excessive fertilizer application and environmental pollution. Current soil phosphorus measurements are labor-intensive, requiring field sampling and lab analysis, and typically capture total phosphorus—including fixed forms—rather than the bioavailable phosphorus that plants can readily absorb. To address these limitations and move towards precision fertilization, we report the early development of hydrogel-based biosensors encapsulating Pseudomonas synxantha 2-79, a bacterium engineered to fluoresce under phosphorus-limited conditions. Two encapsulation strategies were tested based on prior literature to prevent cell leakage into the environment: (1) direct encapsulation within an alginate hydrogel with a polyacrylamide shell, and (2) cell placement within a liquid-containing PDMS chamber covered by a polyacrylamide-alginate hydrogel. We characterized cell viability and growth within both types of encapsulates, examining the fluorescence signal dynamics of the reporter strain in response to varying phosphorus levels in soil-like environments. Our results indicate that hydrogel geometry, especially thickness, significantly influences fluorescence signal quality likely by impacting cell viability and oxygen diffusion within the hydrogel matrix. Furthermore, both encapsulation strategies demonstrated promising stability by effectively limiting cell leakage over extended periods (weeks). Future work will integrate these biosensors with CMOS chip technology for wireless monitoring, laying the groundwork for a field-deployable device. This approach not only addresses phosphorus management in the context of precision agriculture but also serves as a foundation for developing integrated biosensors to detect other key biologically-relevant soil or water parameters, supporting diverse sustainability applications.
This work was funded by the Resnick Sustainability Institute.

12:00-12:20 p.m.: Optimizing Porous PDMS via Freeze-Casting: Enhanced Moduli and Elasticity for Advanced Materials

Kelly Ngyuen*, Jeffery Self

Arizona State University

Polydimethylsiloxane (PDMS) has garnered significant interest due to its unique set of desirable properties, such as processing simplicity, thermal stability, hydrophobicity, and biocompatibility. These properties make PDMS an ideal candidate for a variety of applications—ranging from biomedical devices to pressure sensors. The mechanical properties of PDMS can be further enhanced with the introduction of porosity; the resulting porous elastomers have effectively reduced moduli while retaining their elasticity and stability. There are few methods that enable the production of highly porous PDMS structures, with those typically suffering from process complexity, long processing times, and requiring specialized equipment. Conversely, by leveraging freeze-casting we can facilitate facile processing while also enabling precise control over the final structure and composition. To highlight the generalizability of our method, these studies were done with commercially available PDMS resin: Sylgard 184. Miscibility between the polymer precursors and the porogen are paramount to generating a homogenous solution and encouraging uniform pore formation. Control over composition dictates the final foam structure and properties, with accessible porosities ranging from 40 to 95%. Using scanning electron microscopy, the pore structure can be visualized, with typical pore sizes ranging from 10 to 50 microns. The elastic nature of PDMS is retained through this process, as shown by cyclic compression experiments demonstrating good elastic recovery and high compressibility. Overall, porous PDMS structures synthesized via freeze-casting represent a versatile platform for the development of advanced materials with tunable properties, poised to address the challenges of different fields.