Polymer Science Commons^™

Recovering And Upgrading Kraft Lignin For Application In Flexible Polyurethane Foam, Peng Quan

Dissertations, Master's Theses and Master's Reports

Lignin is the second abundant natural polymer and has been highlighted as a potential substitute for fossil-based raw materials. However, the inherent molecular heterogeneity and the complex recovery processes result in the challenge of controlling the molecular properties and value-added applications of lignin in large scale. To address those issues, a novel acid-liquefaction process was developed in this study to recover Kraft lignin with improved molecular homogeneity directly from black liquor.

In the first study, the liquefaction parameters were screened based on yield and molecular weight properties of the recovered lignin. Then, the recovered lignin samples were used to replace …

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 …

Wetting Transition On 3d-Printed Surfaces, Isabelle Moryan

Williams Honors College, Honors Research Projects

Taking the previous research conducted, this project aims to further the study and research of the wettability of surfaces. Surface features and types are important factors to their wettability. The geometric properties of a surface can make it more hydrophobic and hydrophilic. Extreme cases of hydrophobic and hydrophilic surfaces lead to water repulsion or water absorption, even under extreme conditions. The goal of this project is to gain further insight on how fabricated 3D-printed featured surfaces and examine the wetting transition on these surfaces. In particular, cylindrical pillars will be studied with varied pillar spacing, height and diameter. In addition, …

Application Of Sla 3d Printing For Polymers, Taylor Wilson

Williams Honors College, Honors Research Projects

Stereolithography is a type of 3D printing that allows liquid photopolymer resin to be cured into layers that make up a 3D object. Creation of such resins for these purposes can require a significant amount of time to test and develop, and commercial resins also require some amount of testing for printer settings before use. This paper reviews how stereolithography works, the materials used, and experimentation done to compare the resin properties to the determined curing times. Using several commercially available resins, varying base exposure and layer exposure times were used to determine the lowest possible curing time that gave …

Amine-Functionalized Interpenetrating Polymer Networks For Co2 Capture, James Wills

Williams Honors College, Honors Research Projects

The research performed looked to advance the studies of vacuum swing absorption of Carbon Dioxide to help combat global climate change issues. The focus of the project was to create an anime-polymer sorbent that will weakly absorb and desorb CO2. The sorbent must be durable and be able to withstand multiple uses. The creation of a porous polymer matrix aided in the amines' ability to absorb CO2. Created samples underwent several qualitative and quantitative tests to determine their usefulness as an industrial sorbent. Infrared spectroscopy was used to study the effectiveness of the amine sorbents. Studying the changes in the …

Retention And Stability Of Polystyrene Sulfonic Acid And Polyethylene Glycol Anti- Fouling Films With 3-Aminopropyltriethoxysilane Coupling Agent, Brian Cameron

Williams Honors College, Honors Research Projects

Fouling is a process where particles, proteins, or microorganisms will accumulate onto a material [2]. This can lead to biofilms in medical implants, which can trap and create drug resistant bacteria [5]. Due to this, the study and creation of anti-fouling polymeric films that is stable in aqueous environments is essential. The goal of this study is to utilize APTES to retain the already studied PSS-PEG anti-fouling films. The films that are created is a thermally crosslinked network of the polystyrene sulfonic acid (PSS) and polyethylene glycol (PEG) with differing mass fractions (75- 25 and 55-45 PSS-PEG). To retain the …

Recycled Printer Filament, Charlotte Hyland, Troy D. Molinar

Williams Honors College, Honors Research Projects

The purpose of this research is to examine the effects of recycling PLA filament for 3D printing on its material properties. After examining these effects, PLA and carbon fiber additives were mixed with recycled PLA pellets in different ratios to attempt to regain material properties lost in the recycling process. To complete these findings, an experiment was design and executed.

The research found that tensile strength during multiple iterations of recycling remained mostly unaffected, however, the strain degraded exponentially. In the PLA additive study, high ratios of PLA additive were able to increase the strength and strain properties of the …

Retaining Thermoresponsive Poly(Vinyl Methyl Ether) To Cellulose Via (3-Aminopropyl)Triethoxylsilane Network, Grace Tolhurst

Williams Honors College, Honors Research Projects

Stimuli-responsive supports and devices that are fabricated from inexpensive materials are attractive candidates for a variety of applications, such as environmental protection, and regenerative medicine. Poly(vinyl methyl ether) (PVME), a thermoresponsive polymer (TRP), has recently been used as thermoresponsive cell culture supports for cell growth/proliferation followed with cell/cell sheet harvesting by simply switching temperature. Cellulose is an attractive candidate to replace glass/silicone supports as it is inexpensive and environmentally friendly. This project focuses on retaining PVME to the cellulose membrane via 3-aminopropyltriethoxysilane (APTES) network to generate TR membranes and flexible liners that can be incorporated into bioreactors for producing cells …

Mimicking The Namib Desert Beetle With Hydrophilic And Hydrophobic Surfaces, Tyler Bracewell

Williams Honors College, Honors Research Projects

The Namib Desert beetle, Stenocara gracilipes, condenses fog that rolls in off the west coast of Namibia to provide itself with the water it needs for the day. By lifting its abdomen into the air to collect the water vapor, it condenses on hydrophilic bumps that are about 500μm in diameter and are spaced apart about 500-1500μm. Once the water reaches a critical size, the droplet rolls off the hydrophilic bump and onto the flat hydrophobic surface of the elytra. Since the beetle is angled with its abdomen in the air, the water rolls down to its mouth. A …

Design Project: 3d Printer/Injection Molder Hybrid, Lee Paolucci, Luke Everhart, Brandon Leap, Karson Lorey

Williams Honors College, Honors Research Projects

In the realm of rapid, small-scale prototyping, there are a few main factors that drive decisions to invest resources in technology to make that prototyping possible. Cost and ease of use are two of the most influential when looking at most SMEs (Small to Medium-sized Enterprises). The U.S. Small Business Administration defines an SME as smaller than 1,250 employees. According to An Assessment of Implementation of Entry-Level 3D Printers from the Perspective of Small Businesses, 59% of small manufacturers had implemented 3D printers as of 2014. However, no matter what technology is used in rapid prototyping, there are common …

Development Of Co2 Capture Method Via Polyurethane-Amine Sorbent In Vsa, Samantha Starkey, David S. Rinehart

Williams Honors College, Honors Research Projects

With increases in extreme weather and global temperatures, research is delving into CO₂ capture to help reverse climate change. This project explored utilizing vacuum swing adsorption (VSA) for CO₂ capture and release. VSA uses a sorbent, in this case amine sorbents, to capture CO­­₂ from air and subsequently removes it via vacuum. Polyurethane (PU) foam was investigated as a potential matrix for amine sorbents to increase exposure of CO₂ capturing amines to air by utilizing its porous structure. PU mixing studies were conducted to determine the feasibility of mixing PU foam with amines and coating foams …

Nano-, Encapsulated Manganese Oxide (Nemo) Particles For Mri Enhancement In Microfluidic Tumor Models, Kasey Alexis Freshwater

Graduate Theses, Dissertations, and Problem Reports (ETD)

Breast cancer is among the deadliest cancers in women, with approximately 2.3 million new cases and 685,000 deaths reported globally in 2020 alone. Magnetic Resonance Imaging (MRI) is commonly used to diagnose, stage, and develop treatment plans for patients predisposed to breast cancer. However, current MRI-based screening of breast cancer has high false-positive rates up to 25%, leading to unnecessary invasive follow-up screening and testing. The gold-standard intravenous gadolinium (Gd)-based contrast agents (GBCAs) account for false-positive rates because they are always “ON”, providing a constant MRI signal that highlights both benign and malignant tumors. The work detailed in this thesis …

Development Of Soluble Bioactive Poly(Beta Amino Esters) (Pβaes) For Post-Synthesis Processing, Kelley Wiegman

Theses and Dissertations--Chemical and Materials Engineering

Polymers have proven to be a viable platform to facilitate the controlled and targeted release for a variety of therapeutic agents. Polymeric prodrugs are a growing area of drug delivery in which active pharmaceutical ingredients are covalently linked to a polymeric form in an effort to enhance stability, delivery, and pharmacology. One naturally occurring class of active ingredients, known as polyphenols, can potentially offer a vast array of beneficial therapeutic properties. However, the therapeutic efficacy of these compounds is severely limited due to poor solubility and bioavailability as well as an oxidative and thermal instability. To improve the efficacy of …

Reducing Print Time While Minimizing Loss In Mechanical Properties In Consumer Fdm Parts, Long Le, Mitchel A. Rabsatt, Hamid Eisazadeh, Mona Torabizadeh

Mechanical & Aerospace Engineering Faculty Publications

Fused deposition modeling (FDM), one of various additive manufacturing (AM) technologies, offers a useful and accessible tool for prototyping and manufacturing small volume functional parts. Polylactic acid (PLA) is among the commonly used materials for this process. This study explores the mechanical properties and print time of additively manufactured PLA with consideration to various process parameters. The objective of this study is to optimize the process parameters for the fastest print time possible while minimizing the loss in ultimate strength. Design of experiments (DOE) was employed using a split-plot design with five factors. Analysis of variance (ANOVA) was employed to …

Research Of New Fireproof Supplied Polymer Composites Based On Epoxy Resin For Metal Structures, Kuvondiq Murtazaev, F.N. Nurkulov, D.N. Mukhiddinov, M.T. Аbdirova

Technical science and innovation

In the article proposes new compositions based on fire retardant expanded polymer composites of epoxy resin ED-20 and phosphorus-containing oligomers, catalysts, aluminum hydroxide and nitrogen-containing compounds.

The obtained sample of fire retardant expanded polymer composites based on epoxy resin, as well as the initial substances, were investigated by IR spectroscopy (Nicolet 5700), thermogravimetric analysis (TG) (SDT Q600) of physical and chemical properties and determination of fire retardant efficiency according to GOST R 53295-2009.

Infrared spectroscopy has been used to determine the bends and epoxy groups that characterize composites, as well as to determine the frequencies of phosphorus, nitrogen, and metal-containing …

Development Of Polymeric Cxcr4 Targeting Carriers For Sirna Delivery To Treat Acute Kidney Injury, Weimin Tang

Theses & Dissertations

Acute kidney injury (AKI) is a major kidney disease that is characterized by a sudden loss of renal function which manifests by a decrease in urine output and an increase in serum creatinine. AKI is a global healthcare burden associated with high morbidity, mortality, and increasing cost. Currently there are no effective pharmacological treatments available. Apoptosis induced by p53 has been demonstrated as an important pathological mechanism for the development of AKI. Meanwhile, CXCR4/SDF-1 axis has been associated with the inflammation during AKI, and CXCR4 is overexpressed on injured tubules. This dissertation hypothesized that polycations with CXCR4 targeting ability could …

Polymeric Nanofibers Supported Metal Oxides For Electrochemical Energy Storage Devices, Rutul Patel

Electronic Theses & Dissertations

With increasing demand for energy, there is an increased need to find effective ways to store the available energy to sustain current and future generations. Thus, the research investigates whether polymetric nanofibers support metal oxide are a good solution to store energy. The materials used for synthesis includes N-dimethylformamide, nickel nitrate, cobalt nitrate and polyacrylonitrile.

These fibers are developed three phases. First, a homogenous mixture is prepared, followed by electrospinning of the mixture. Next, calcination of the prepared nanofibers was done to generate the 1D nanofibers embedded with metal oxides. The samples are primarily tested for supercapacitor applications, hydrogen evolution …

Water Recovery From Bioreactor Mixed Liquors Using Forward Osmosis With Polyelectrolyte Draw Solutions, Calen Raulerson

All Theses

The objective of this research was to test the feasibility of using forward osmosis (FO) with polyelectrolyte draw solutions to recover water from bioreactor mixed liquors. When combined with an Anaerobic Osmotic Membrane Bioreactor (AnOMBR), such a system could process fecal and food waste from astronauts aboard the International Space Station (ISS) and reclaim important nutrients and water. This project focused on measuring the obtainable water recovery rates from bioreactor effluent, and the identifying challenges associated with the operation.

AnOMBRs feature several advantages over aerobic bioreactors, and non-osmotic anaerobic membrane bioreactors (AnMBR). Anaerobic bioreactors avoid the significant energy costs of …

Approaching Disorder-Tolerant Semiconducting Polymers, Xinwen Yan, Miao Xiong, Xin Yu Deng, Kai Kai Liu, Jia Tong Li, Xue Qing Wang, Song Zhang, Nathaniel Prine, Zhuoqiong Zhang, Wanying Huang, Yishan Wang, Jie Yu Wang, Xiaodan Gu, Shu Kong So, Jia Zhu, Ting Lei

Faculty Publications

Doping has been widely used to control the charge carrier concentration in organic semiconductors. However, in conjugated polymers, n-doping is often limited by the tradeoff between doping efficiency and charge carrier mobilities, since dopants often randomly distribute within polymers, leading to significant structural and energetic disorder. Here, we screen a large number of polymer building block combinations and explore the possibility of designing n-type conjugated polymers with good tolerance to dopant-induced disorder. We show that a carefully designed conjugated polymer with a single dominant planar backbone conformation, high torsional barrier at each dihedral angle, and zigzag backbone curvature is highly …

Extraction Methodologies And Physicochemical Characterizations Of Nanocellulose Isolated From Kudzu For Potential Sustainable Packaging Applications, Elliott Love

All Theses

Flexible packaging is an integral part of the food supply chain due to its unique thermal, mechanical, and barrier properties. The many advantages (e.g., lightweight, product protection, reduction in food waste, communication medium, etc.) come with certain drawbacks (low recyclability rate, pollution of ecosystems, etc.). Still, the heavy reliance of the food industry on these products, many of them being non-sustainable polyolefins, is unlikely to diminish in the foreseeable future. Thus, more sustainable alternatives that do not sacrifice performance (machinability, shelf-life, etc.) are needed before pollution becomes irreversible and public outcry insurmountable. Nanocellulose, especially in the form of cellulose nanocrystals …