Polymer Science Commons^™

Molecular Origins Of Non-Frozen Water In Polyelectrolyte Brushes, Ali Dhinojwala, Saveen Jayaweera, Md Golam Kibria, George Mallinos

University Research

Polyelectrolyte brushes (PEBs) are promising coatings for reducing ice adhesion and regulating water freezing at interfaces, yet direct measurements of nonfrozen water retention at subzero temperatures remain scarce. Here, we investigate the freezing behavior of water confined in poly([2-(methacryloyloxy)ethyl]trimethylammonium) (PMETA) brushes with chloride, iodide, and sulfate counterions using a custom-built low-temperature attenuated total reflectance infrared spectroscopy system. Furthermore, we quantify the fraction of water that was present within the brush that does not freeze as well as the changes in polymer volume fraction within the brush as a function of temperature. Spectroscopic analysis of water vibrational modes reveals that PMETA …

Transient Grating Spectroscopy Nondestructively Characterizes The Mechanics Of Rubbery Polymers And Soft Gels, Christopher W. Barney, Angela A. Pitenis, Bolin Liao, Allison L. Chau

University Research

Designing efficient mechanisms for moving mechanical assemblies requires the use of materials with well-defined mechanical responses. Appropriate methods are needed to characterize these mechanical responses. Mechanical characterization of soft materials is critical in the high strain rate regime where intuition from manipulating a material at low rates fails to translate to applications including impact protection, tire traction, and sound damping. Here, transient grating spectroscopy (TGS) is used to measure wave propagation for soft elastomers and hydrogels. TGS is a non-destructive and non-contact optoacoustic technique that enables high strain rate measurements of the bulk modulus, a measure of a material's resistance …

The Role Of Side-Chain Length And Counterion Mediation On Dimerization Of Rigid Sphere-Rod Amphiphiles: A Molecular Dynamics Investigation, Mesfin Tsige, Tianbo Liu, Javad Tamnanloo, Abdol Hadi Mokarizadeh

University Research

Rigid sphere-rod amphiphiles (RSRAs) comprising a Keggin polyoxometalate (POM) headgroup and an oligofluorene rod with different side chain lengths (C2, C6, C10, C16, are the number of carbon atoms per side chain) were probed by all-atom molecular dynamics in THF/water mixtures (15 and 33 vol % THF) with tetrabutylammonium (TBA+) counterions to elucidate the molecular origins of dimerization. Despite strong Keggin-Keggin electrostatic repulsion, stable dimers form through a synergy of (i) hydrophobic rod/side-chain interaction that strengthens with side-chain length and (ii) counterion-mediated attraction by TBA+, which localizes near the Keggins to screen electrostatic repulsion. Packing evolves from near-parallel rods for …

Made On Mars: Design And Manufacturing Of Structural Polymer-Regolith Composites, Pailey M. Vitale

Williams Honors College, Honors Research Projects

Human exploration of Mars is constrained by harsh environmental conditions and the prohibitive cost of transporting materials from Earth. Long-term sustainability requires the local production of mechanical and structural components using resources available on Mars, thereby minimizing payload mass. This project investigates polymer–regolith composites derived from atmospheric CO₂ and mineral-rich regolith as a pathway toward in-situ manufacturing. These composites, when compatible with additive manufacturing, could replace imported plastics, enable on-demand fabrication, and support closed-loop recycling systems. The objective is to design and evaluate polymer–regolith composites that maintain mechanical integrity and environmental resistance under Martian conditions, including extreme temperature swings, radiation …

Energy Efficient Windows Using Pvme, James S. Bronstrup

Williams Honors College, Honors Research Projects

This Honors Project aims to improve window energy efficiency using the thermoplastic polymer PVME (polyvinyl methyl ether), which displays temperature-dependent transparency that can be adjusted by mixing it with water and salt to reduce heat transfer through a window. The objective is to determine the optimal PVME water-salt ratios for placement inside a windowpane, evaluate energy savings compared to a traditional argon-filled window, and compare estimated costs. A small-scale model will test different concentrations for various climates, with heat transfer measured by temperature indicators via a LabQuest. Building on research by Yang Zhou at Nanyang Technological University, who used a …

Microscopic Insights On Shear Rheology Of Polyampholyte Ionomers Via Molecular Simulations, Kyle Vonscio

Williams Honors College, Honors Research Projects

Ionomers are polymers that contain a small fraction of charged groups. The ionic attraction of charged groups allows ionomers to act similarly to crosslinked polymers. Depending on the strength of electrostatic interactions and structure of the ionomers, different dynamics and rheological responses can be observed. With moderate attraction between ions, these noncovalent crosslinks can be broken when heated, allowing ionomers to flow and show the strength of a crosslinked network at low temperatures. Nonequilibrium molecular dynamics (NEMD) simulations will be performed under shear in the xy-plane and the macroscopic rheology and conformation of the polyampholyte ionomer will be determined. The …

Analyzing The Effect Of Network Properties On Self-Assembly Of Polymer Grafted Nanoparticles In Vitrimer Nanocomposites, Tyler Eakin

Williams Honors College, Honors Research Projects

This project aims to show the how polymer grafted nanoparticles behave in a vitrimer composite network. The effect of varying the network parameters such as the grafting density, the volume fraction of nanoparticles, and the ratio of polymer chain length : graft chain length will be studied. The assemblies formed by the polymer grafted nanoparticles will be visually analyzed and assigned one of 5 possible conformations. A phase diagram of grafting density vs network chain length / graft length will be constructed. The phase diagram will provide valuable insight into how nanoparticle self-assembly can be manipulated through changing network parameters

Effects Of Hofmeister Ions On Lower Critical Solution Temperatures Of Poly(N-Isopropylacrylamide) And Poly(Vinyl Methyl Ether), Joseph Joaquin

Williams Honors College, Honors Research Projects

The goal of this study is to compare how four different Hofmeister anions (Cl-, SCN-, F-, and I-) affect the Lower Critical Solution temperature (LCST) on two thermo-responsive polymers: poly(N-isopropylacrylamide) (pNIPAAM) and poly(vinyl methyl ether) (PVME). pNIPAAm is commonly used in the environmental applications such as monitoring, oil-water separations, or antifouling materials, and in medical industry from drug delivery to tissue engineering. When pNIPAAM or PVME reaches a temperature above their LCST, they become hydrophobic, and the polymer chains coiled, leading to their aqueous solutions turn opaque. PVME exhibits a similar LCST as that of pNIPAAM, so it can be …

Surface Immobilization Of Stimuli-Responsive Polymers Using A Network Of Aminopropyltriethoxysilane, Walter Bungard, Ryan Nixon

Williams Honors College, Honors Research Projects

The goal of this honors project is to develop a cost-effective and accessible method for entrapping stimuli-responsive polymers onto solid substrates using aminopropyltriethoxysilane (APTES). The entrapment network process will first be replicated on glass or silicon using APTES and poly(N-isopropylacrylamide), involving spin coating and thermal annealing to chemically bond the polymer to the substrate. Once validated, the method will be applied to other stimuli-responsive polymers, including thermo-responsive, electroactive, and pH-sensitive types, with APTES as a control. For each sample, film stability, responsiveness, and surface behavior will be evaluated using contact angles, optical microscopy, and spectroscopic analysis, followed by statistical evaluation. …

Damage Behavior In Unidirectional Cfrp Laminates With Ply Discontinuity, M.J. Mohammad Fikry, K. T. Tan, Yutaro Arai, Ryo Inoue

University Research

This study presents a comprehensive quantitative investigation into the material properties and damage behavior of unidirectional carbon fiber reinforced plastic laminates with ply discontinuities. Laminates with varying resin gap lengths were evaluated. In situ edge observations and X-ray computed tomography were employed to assess the damage processes in the area of the ply discontinuity. These methods examined initially occurring cracks, secondary cracks, and delamination. Some unexpected cracking behavior was observed in this study. For instance, initial cracks were observed to form not at the interface but at a distance from the resin–ply interface, likely due to a constraint condition caused …

Prediction Of Glass Transition Temperature Of Polymers Using Structure-Based Models, Nicholas Wolfe

Williams Honors College, Honors Research Projects

The focus for this study is prediction of glass transition temperatures of polymers using machine learning models. The preprocessing of the data included the generation of descriptors, the scaling of the data, the principal component analysis for dimensionality reduction, and the clustering of the data. Three methods of property predictions were utilized including Linear Regression, Random Forest, and a Feedforward Neural Network. The dataset consisted of over 7000 polymers each with their respective glass transition temperatures. This study found that the Random Forest model returned the best results followed by the Feedforward Neural Network then the Linear Regression model. Each …

Modeling The Thermodynamics Of Butadiene And Carbon Dioxide Coupling Reactions, Alexis Sarantos

Williams Honors College, Honors Research Projects

This project will analyze the synthesis reaction of ethenylated 𝛿-valerolactone (EVL), specifically to determine certain thermodynamic properties of EVL and its coproducts. The thermodynamic properties of the reaction products can then be utilized to make the development of a large-scale process simpler and safer. The properties that will be determined are the heats of formations, heat capacities, and changes in enthalpy caused by each product during the reaction, and these will be used to determine whether the energy produced by the reaction is sufficient to maintain formation of the desired product. Additionally, a process model of heat flows and energy …

Effects Of Polyolefin Types On Catalytic Hydrocracking, Kenneth Jackson Seeber

Williams Honors College, Honors Research Projects

Plastic waste recycling has become an important conversation in the last couple of decades with pollution on the rise. One of the few ways to recycle plastics is by breaking these long-chained polymers down via catalytic processes. Due to many plastic products being a blend, it is imperative that any chosen catalyst that could be used for recycling should be able to handle different types of polymers. This paper discusses how tungsten carbide over silica (W_xC/SiO₂) catalyzes the degradation of a few selected polymers and polymer blends. From this research it was determined that W_{x …}

Polystyrene Plastic Waste As An Organic Hydrogen Carrier, Alaina Bachmann

Williams Honors College, Honors Research Projects

The proposed research develops and studies catalytic chemical processes that enables using polystyrene (PS) plastic waste as solid “organic hydrogen carriers” (OHC). Demands for OHCs are driven by desire to alleviate climate change, by replacing carbon-based energy sources with hydrogen. However, hydrogen is highly flammable and difficult to store and transport so OHCs are needed to facilitate its transportation. Common OHCs are liquid petroleum chemicals with unsaturated chemical structures. They can be hydrogenated to store hydrogen and dehydronated to release hydrogen at desired application sites. The proposed research aims to investigate the following cycle: hydrogen storage by hydrogenation of PS …

Optimized Pi Compound Mixing Strategy, Cecilia Mainzer

Williams Honors College, Honors Research Projects

The project focuses on developing an optimal mixing strategy for a polyisoprene (PI) compound at the Goodyear Tire & Rubber Company. The aim is to optimize performance objectives of the compound. The project involved research, design iterations, mixing analyses, and performance evaluations, while adhering to engineering codes and standards.

The design process includes analyzing differences between two mixing technologies, intermesh and tangential rotors; altering mixing conditions; and exploring additional polymer systems and coupling technology of the compound.

Validation data confirms that the mixing technology and compound recipe meets all success metrics, including stiffness, hysteresis, adhesion, cure rate, and tear performance …

The Effects Of Relative Humidity And Valency On Water Absorption And Structure In Polyelectrolyte Brushes, Andrea Klima

Williams Honors College, Honors Research Projects

The purpose of this project was to understand the relationship between relative humidity, ion valency, and the structure of water on positively (PMETAC) and negatively (PSPMA) charged polyelectrolyte brushes. The polyelectrolyte brushes were synthesized using Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP) and were soaked in concentrations containing 0.1 M of the target counterion. The brushes were then exposed to humid vapor, and spectra were collected in 5% intervals between 0% and 85% for each counterion. Two trials were completed for each counterion studied to ensure agreement between datasets. In all spectra, peaks appeared for the …

Schaeffler Icvd Coating Machine, Louis Mcgrath

Williams Honors College, Honors Research Projects

Chemical Vapor Deposition (CVD) is mutual technology used to deposit thin film through a gaseous phase by vaporizing the solid materials. This conventional process usually requires high thermal stability of the materials, which is not applicable for most of the polymeric materials. Therefore, a novel process, initiated Chemical Vapor Deposition (iCVD) is developed by introducing the gaseous monument and initiator to form the thin film in-situ. By adjusting the free-radical polymerization in the vapor phase, a variety of thin and uniform polymer films can be achieved. Depending on the chemistry, iCVD has many categories. This report explains the design …

Degradable Staples And Delivery Device, Meha Elango, Jessica Cabrera, Makayla Scarpitti, Kareemat Melaiye

Williams Honors College, Honors Research Projects

The scope of this project is to design a method to secure skin grafts to healthy tissue. The ultimate goal for the proposed method is to be dissolvable in some form. Currently, skin grafts procedures utilize staples in most cases to hold a skin graft in place, but there are disadvantages that come with it. Staples are easy to place, but time consuming during the removal procedure. They also cause a lot of pain and discomfort for the patient. The goal of this project is to determine a way a secure skin grafts to healthy skin in order to reduce …

Construction Composites Of Recycled Pvc And Recycled Polyolefins, Natalie Prusovic

Williams Honors College, Honors Research Projects

Current construction composites are typically only composed of polyvinyl chloride (PVC) and recycled PVC (rPVC). This proposed project will investigate if recycled polyethylene (rPE) and polypropylene (rPP) can be used instead of PVC in those materials. Different compositions of rPE, rPP, and rPVC blends will be compounded and a T-peel test will be performed to test the adhesion.

Exploring Natural Raw Materials For The Development Of Hot Melt Adhesives For Linings Of Paintings, Erica Factor

Williams Honors College, Honors Research Projects

Natural raw materials will be explored for developing hot melt adhesives for the lining of paintings. The leading raw material is a natural resin called "Damar". This resin is obtained from the tree family Dipterocaupocea in India and Southeast Asia. This material has shown promising results from initial testing. Damar, with the potential for other natural raw materials, will be combined with synthetic ingredients to create sustainable formulations. The formulations will be tested on linen to replicate the application onto paintings. The sustainability, tackiness, texture, and overall performance of each formula will be considered. Once a formulation has been selected, …

Removal Of Residual Stress In 3d Printed Polymers, Christian Jenkins

Williams Honors College, Honors Research Projects

This project aims to investigate the relationship between stress relaxation and the reduction of dimensional shrinkage and warping in 3D printed polymers produced through fused filament fabrication. The hypothesis suggests that residual stress in 3D printed structures results from factors such as temperature differences, molecular-level contributions, and rapid cooling, causing post-printing warpage and damage. To mitigate these issues, the project proposes annealing 3D printed polymers in a hot sandbath to allow stress relaxation without warping. The study will employ a Dynamic Mechanical Analysis (DMA) machine to assess mechanical properties of relaxed and unrelaxed samples, comparing their effectiveness. The project's timeline …

Comparing Weathering Effects Of Ultraviolet And Xenon Arc Accelerated Aging On Polyvinyl Chloride, Collin Mcinnes

Williams Honors College, Honors Research Projects

As the ubiquitousness of polymers increases and begins seeing use in outdoor settings, the need to fully understand how these materials degrade is also necessary. This study aims to compare two known accelerated aging methods, namely an ultraviolet light chamber and a xenon arc light chamber, to understand what differences, if any, manifest in the mechanical, chemical, and cosmetic deterioration of polyvinyl chloride (PVC) after long-term exposure. The study utilizes Fourier-transform infrared spectroscopy, dynamic mechanical analysis, thermogravimetric analysis, and colorimetry analysis to determine the extent of degradation and potential discrepancies between the aging methods.

Running Shoe Pedometer, Benjamin Kasper

Williams Honors College, Honors Research Projects

Running shoe pedometer aims to solve the issue of worn out running shoes. It can be difficult to know just how many miles you have run in your shoes and when a new pair is needed. Running in old shoes and worn out shoes is heavily linked to injury. My proposed project is a device that is powered by the compressive forces on the shoes soles that counts the number of steps the wearer takes using a microcontroller. Then, when the shoe reaches milestone that indicate it has been used 75% 90% and 100% of its expected life, it will …

Beeswax Wraps As An Alternative To Single-Use Plastics, Sarah Skiver

Williams Honors College, Honors Research Projects

The project goal was to compare the food storage efficacy of sustainable beeswax wraps verses the single-use plastic methods of resealable plastic sandwich bags and plastic cling wrap. The goal was also to test the reusability of the beeswax wraps, as it is a key advantage of beeswax wraps that is advertised. The project purpose was to explore sustainable and eco-friendly alternatives to single use plastics, which are harmful to the environment in both their production and their disposal. Food spoilage was compared in beeswax wrap, plastic sandwich bags, and plastic cling wrap, and spoilage was also observed in a …

Structural Design And Application Of Polymeric Silicon Elastomers, Jacob Wyant

Williams Honors College, Honors Research Projects

The purpose of this project was to determine how the polymeric structure and mechanical properties of this elastomer are affected by the ratio between the polydimethylsiloxane macromolecular chains and the crosslinkers. These were determined via tensile and compression testing. Then, spiropyran was added to observe how this fluorescence and crosslinking agent affected the elastomer. Also, the elastomer’s fluorescent and icephobic nature were tested. The elastomers with a higher ratio of crosslinker to macromolecular chain could withstand higher tensile and compressive strains but failed at lower stresses than their counterparts with lower concentrations of crosslinkers. The elastomers were also found to …

Defining The Proper Operating Time For The Septa Extractor, Abigail Jones

Williams Honors College, Honors Research Projects

Anionic polymerizations are a common type of reaction used to produce synthetic rubber. During these reactions, it is necessary to charge initiators, modifiers, and other substances, through pressurized containers that are sealed with rubber septa. These septa prevent oxygen and moisture from entering the pressurized container, and the reactor, though they need to be cleaned before use to remove other impurities. Currently a glass Soxhlet Extractor is used to remove such impurities, and though effective, it has a limited capacity, so it has to run frequently. This limitation led to the commissioning of the Septa Extractor, which is an automated …

Anti-Freeze Double Network Hydrogels, William Gross

Williams Honors College, Honors Research Projects

Three polyethylene glycol (PEG) based crosslinkers with repeat unit nominal weights of 62.1, 200, and 400 g/mol in agar/PAM double network (DN) hydrogels were used to study the effect of different crosslinkers on thermal and mechanical properties. Using the one-pot synthesis method, hydrogels with the PEG crosslinkers or methylene-bis-acrylamide (MBAA) were made via sol-gel transition for formation of agar network, and photopolymerization of the PAM network using Irgacure 2959 as photo initiator. Tensile and compression tests were performed on as prepared, swollen, and swollen & cooled specimens of each hydrogel. Freezing time and thermal imaging were performed in -20 °C …

Utilizing Computer-Aided Molecular Design With Azido-Ester Plasticizers, Justin Ebert

Williams Honors College, Honors Research Projects

The goal of this project was to utilize Computer-Aided Molecular Design (CAMD) using the Signature molecular descriptor to inversely design optimized azido-ester plasticizers. Azido-ester plasticizers are used to modify the mechanical properties of propellant and explosive formulations. With the assistance of quantitative structure-property relationships, QSPRs, and two types of constraint equations, these new, novel plasticizers have the potential to possess optimal physical and chemical properties. Properties investigated in this work were decomposition temperature, heat of formation, glass transition temperature, and molecular weight. These properties were chosen for their importance when formulating propellants or explosives. After the filters were applied to …

Reinforcement Of Elastomers By Reactive Ionic Surfactant, Nicole Vickerman

Williams Honors College, Honors Research Projects

Elastomers without cross-linking agents or fillers do not have the necessary properties for practical applications in the rubber industry. Elastomers must be reinforced with fillers and/or cross-linking agents to achieve the needs of physical and mechanical properties for commercial products. Sodium octyl 6-mercaptohexyl phosphate (SOMP) and sodium ethyl (6-mercaptohexyl) phosphate (SEMP) were used to investigate the influence of a reactive ionic surfactant and its influence on the physical properties of peroxide crosslinked styrene butadiene rubber (SBR). SEMP and SOMP were both found to be able to be grafted successfully on to the SBR chains within the rubber using extraction testing …

Amino-Polymer For Co2 Capture By Vacuum Swing Adsorption, Sean Billy

Williams Honors College, Honors Research Projects

The applications of sorbent compounds in conjunction with amines and other additives is an innovative method at combating CO2 pollution. An ideal solution would use an amine sorbent to trap the high levels of absorbed CO2 with a low binding energy (less than 45 kJ/mol) and subsequently release them into a stored vessel at ambient temperature with a vacuum swing adsorption system. Attempts at finding a best mixture will be conducted through the usage of a vacuum swing system, utilizing a bed syringe containing the sorbent mix and a vacuum syringe to pull on and subsequently release the CO2 into …