Polymer Science Commons^™

Bimetallic Nanoparticles Integrated Membranes For Groundwater Remediation: Synthesis, Characterization And Applications, Hongyi Wan

Theses and Dissertations--Chemical and Materials Engineering

The detoxification of chlorinated organics from groundwater, such as trichloroethylene (TCE), tetrachloroethylene (PCE), polychlorinated biphenyl (PCB) and carbon tetrachloride (CTC), is a challenging area. Reductive dechlorination has been investigated using iron and iron-based nanoparticles, such as bare Fe, sulfidized Fe (S-Fe) and palladized Fe (Pd-Fe). However, issues including particle agglomeration, difficulties in recycling and particle leaching have been reported to hinder the application and wide usage of these techniques. The integration of nanoparticles and membranes can address these issues because of the large surface area, stability, and the potential for versatile functionalities. In this study, commercial polyvinylidene difluoride (PVDF) microfiltration …

Polymeric Nanocomposite Membranes With Phosphorene Based Pore Fillers For Fouling Control, Joyner Eke

Theses and Dissertations--Chemical and Materials Engineering

Phosphorene is a two-dimensional material exfoliated from bulk phosphorus. Specifically, relevant to the field of membrane science, the band gap of phosphorene provides it with potential photocatalytic properties, which could be explored in making reactive membranes able to control the accumulation of compounds on the surface during filtration, or fouling. Another reason phosphorene is a promising candidate as a membrane material additive is due to its catalytic properties which can potentially destroy foulants on the membrane surface.

The first goal of this study was to develop an innovative and robust membrane able to control and reverse fouling with minimal changes …

Formulation And Validation Of Nanoparticle Controlled Delivery For Chemotherapeutic Drug Products, Shani L. Levit

Theses and Dissertations

Taxol, a formulation of paclitaxel (PTX), is one of the most widely used anticancer drugs, particularly for treating recurring ovarian carcinomas following surgery. Clinically, PTX is used in combination with other drugs such as lapatinib (LAP) to increase treatment efficacy. Delivering drug combinations with nanoparticles has the potential to improve chemotherapy outcomes. In this study, we use Flash NanoPrecipitation, a rapid, scalable process to encapsulate weakly hydrophobic drugs (logP in vitro. Encapsulating either PTX or LAP into nanoparticles increases drug potency. When PTX and LAP are co-loaded in the same nanoparticle, they have a synergistic effect that is greater than …

Homotopy Simulation Of Dissipative Micropolar Flow And Heat Transfer From A Two-Dimensional Body With Heat Sink Effect: Applications In Polymer Coating, O. A. Bég, B. Vasu, A. K. Ray, T. A. Beg, A. Kadir, H. J. Leonard, Rama S. R. Gorla

Faculty Publications

Non-Newtonian flow from a wedge constitutes a fundamental problem in chemical engineering systems and is relevant to processing of polymers, coating systems, etc. Motivated by such applications, the homotopy analysis method (HAM) was employed to obtain semi-analytical solutions for thermal convection boundary layer flow of incompressible micropolar fluid from a two-dimensional body (wedge). Viscous dissipation and heat sink effects were included. The non-dimensional boundary value problem emerges as a system of nonlinear coupled ordinary differential equations, by virtue of suitable coordinate transformations. The so-called Falkner-Skan flow cases are elaborated. Validation of the HAM solutions was achieved with earlier simpler models, …

Innovative Sustainable Wood Preservatives From Pulp And Paper Industry Byproduct, Raisa Carmen Andeme Ela

Dissertations, Master's Theses and Master's Reports

In the modern forest industry, the need for bio-based, renewable, and environmentally-benign wood preservatives is increasing. Preservatives are used to prevent or limit decay and there has been an increasing interest in developing wood preservatives from renewable materials. To support the need for bio-based, environmentally-friendly preservatives, this work employed kraft lignin as a raw material to produce a novel bio-based wood preservative.

For the first project, a statistical design of experiments approach in Minitab® was used to study how fractionation process variables during acid precipitation of lignin influence the lignin mass yield and characteristics. After precipitating lignin from black liquor, …

Exploring Shape-Memory Polymers From Silicone I And 1,10-Decanediol Blends, Kristina Nguyen

Williams Honors College, Honors Research Projects

Shape-memory polymers (SMPs) are polymeric materials that have dual-shape capabilities. These materials can deform to a temporary shape and will recover to their permanent original shape when induced by an external stimulus such as heat. The purpose of this project was to investigate the thermo-mechanical properties and shape-memory behavior of various blends of Silicone I and 1,10-decanediol to determine if a unique blend of these components can be utilized to develop shape memory surface relief patterns.

Careful iterative experiments were used to develop a robust procedure for the fabrication of crosslinked sheets of blends of Silicone I and 1,10-decanediol over …

Methods For Film Coating Electrospun Fibers, Kristopher Dejean

Williams Honors College, Honors Research Projects

Electrospinning uses high voltages to form polymer nanofiber membranes. These membranes have potential for use in filtration, tissue engineering, drug delivery, and catalysis. The nonwoven fiber mat is malleable but has a low tensile strength compared to a solid film of the same polymer. Joining the fibers with a thin film is desired to balance the strength and flexibility. Three methods of producing a film on fiber membrane were tested. The techniques are spraying then melting, spin coating, and dip coating. Electrospinning setup conditions, solvent ratios, damage to fibers, and spin coating speeds were determined. Research was abruptly stopped and …

Fabrication, Characterization And Applications Of Highly Conductive Wet-Spun Pedot:Pss Fibers, Ruben Sarabia Riquelme

Theses and Dissertations--Chemical and Materials Engineering

Smart electronic textiles cross conventional uses to include functionalities such as light emission, health monitoring, climate control, sensing, storage and conversion of energy, etc. New fibers and yarns that are electrically conductive and mechanically robust are needed as fundamental building blocks for these next generation textiles.

Conjugated polymers are promising candidates in the field of electronic textiles because they are made of earth-abundant, inexpensive elements, have good mechanical properties and flexibility, and can be processed using low-cost large-scale solution processing methods. Currently, the main method to fabricate electrically conductive fibers or yarns from conjugated polymers is the deposition of the …

A Thermodynamic And Feasibility Study Of Green Solvents For The Fabrication Of Water Treatment Membranes, Xiaobo Dong

Theses and Dissertations--Chemical and Materials Engineering

Nonsolvent induced phase separation (NIPS) has been widely used to fabricate polymeric membranes. In NIPS, a polymer is dissolved in a solvent to form a dope solution, which is then cast on a substrate and immersed in a nonsolvent bath, where phase inversion occurs. Petroleum-derived organic solvents, such as N-Methyl-2-Pyrrolidone (NMP) and Dimethylacetamide (DMAc), have been traditionally used to fabricate polymeric membranes via NIPS. However, these solvents may have negative impacts on environmental and human health; therefore, using greener and less toxic solvents, preferably derived from biomass, is of great interest to make membrane fabrication sustainable. In this dissertation, two …

Gravity-Drawing Flexible Silicone Filaments As Fiber Optics And Model Foldamers, Katherine Snell

CMC Senior Theses

Here, we present a method of gravity-drawing polydimethylsiloxane (PDMS) silicone fibers with application as fiber optics and as model foldamers. Beginning as a viscous liquid, PDMS is cured using heat until its measured viscosity reaches 4000 mPa•s. The semi-cured elastomer is then extruded through a tube furnace to produce thin (diameters on the order of hundred micrometers) filaments with scalable lengths. PDMS is biocompatible, gas-permeable, flexible, and hydrophobic. Additionally, the PDMS surface hydrophobicity can be modified via UV exposure, O2 plasma, and corona discharge. We demonstrate the patternibility (i.e patterns of hydrophobicity) of PDMS fibers, adding complexity to potential foldamer …

Time-Dependent Reliability Framework For Durability Design Of Frp Composites, Rajneesh Kumar Bharil

Graduate Theses, Dissertations, and Problem Reports

The life-cycle performance, durability, and aging characteristics of Fiber Reinforced Polymer (FRP or Structural Composites) have been of keen interest to the engineers engaged in the FRP design, construction, and manufacturing. Unlike conventional construction materials such as steel and concrete, the design guidelines to account for the aging of FRP are somewhat scattered or not available in an approved or consistent format. Loss of strength over time or aging of any structural material should be of concern to engineers as the in-service lifespan of many engineering structures is expected to exceed 100 years. Use of durability strength-reduction factors or factors …

Elucidating The Properties And Mechanism For Cellulose Dissolution In Tetrabutylphosphonium-Based Ionic Liquids Using High Concentrations Of Water, Brad Crawford

Graduate Theses, Dissertations, and Problem Reports

The structural, transport, and thermodynamic properties related to cellulose dissolution by tetrabutylphosphonium chloride (TBPCl) and tetrabutylphosphonium hydroxide (TBPH)-water mixtures have been calculated via molecular dynamics simulations. For both ionic liquid (IL)-water solutions, water veins begin to form between the TBPs interlocking arms at 80 mol % water, opening a pathway for the diffusion of the anions, cations, and water. The water veins allow for a diffusion regime shift in the concentration region from 80 to 92.5 mol % water, providing a higher probability of solvent interaction with the dissolving cellulose strand. The hydrogen bonding was compared between small and large …

Evaluating Rubber Aging On Tire Durability: Quantitative Evaluation Of Rubber Aging, Brian Auffenberg

Williams Honors College, Honors Research Projects

Rubber is considered one of the most important polymers in the world due to its variety of uses. There are many different conditions that can affect the useful life of rubber. The purpose of this research was to determine how the mechanical loading on the rubber may affect the aging of the rubber. The scope of the project was to focus on the rubber used for tire production. The research was limited to focusing only on rubber supplied by industry mentors which was styrene-butadiene rubber. By varying the length of time for testing as well as the temperature of the …

Design Of Pigments For Use In “Cool” Coatings, Tyler Laughorn

Williams Honors College, Honors Research Projects

This project was focused on the development and testing of several novel pigments that exhibit high NIR-reflectance and therefore show potential for use in “cool” coatings. A “cool” coating will reflect more solar radiation than other standard coatings, and so a coated structure would require less energy to keep cool. Four sets of pigments were synthesized: Co_1-xMg_xCr₂O₄ (teal), Co_0.25Mg_0.75Cr_2-yAl_yO₄ (blue), Ti_1-x-yNi_xSb_yO₂ (yellow), and Cr_2-xFe_xO₃ (black). NIR and TSR values were then measured …

Methods For Film Coating Electrospun Fibers, Kristopher Dejean

Williams Honors College, Honors Research Projects

Electrospinning uses high voltages to form polymer nanofiber membranes. These membranes have potential for use in filtration, tissue engineering, drug delivery, and catalysis. The nonwoven fiber mat is malleable but has a low tensile strength compared to a solid film of the same polymer. Joining the fibers with a thin film is desired to balance the strength and flexibility. Three methods of producing a film on fiber membrane were tested. The techniques are spraying then melting, spin coating, and dip coating. Electrospinning setup conditions, solvent ratios, damage to fibers, and spin coating speeds were determined. Research was abruptly stopped and …

A Comparison Of Fiber Mat Thickness Measurement Techniques Using Laser Interferometry And Water Displacement, Ryan Seabeck

Williams Honors College, Honors Research Projects

Polymer fiber mats may often be very thin which leads to complications in measuring thickness. The thickness of fiber mats, however, is crucial in understanding their behavior. Thickness affects how well the mat works as a filter as well as the pressure drop across the mat, and herein lies the need for accurate measurement techniques. Currently two of the available techniques for measuring mat thickness are by laser interferometry[1] and by buoyancy force when submerged in water[2]. Instead of measuring the buoyancy force in this experiment, an enclosure intended to measure the thickness via water displacement was …

Filtration Apparatus Design For Oil-Water Separation Using Membranes And Sponges, Alec Jerger

Williams Honors College, Honors Research Projects

It can be difficult to separate water and oil emulsions through traditional filtration. Therefore, investigations of filtering using thermo-responsive (TR) polymers, in this case poly(vinyl methyl ether) (PVME), was conducted. It’s hypothesized that below its lower critical solution temperature (LCST), PVME has an affinity for water while oil substances do not. Above the LCST the opposite will be true. To verify this hypothesis, iterations of filtration designs were created to provide optimum control over the parameters to measure flow. The final optimized experimental apparatus was a Chromaflex glass column which was air tight and controlled all parameters besides fluid flow. …

Effects Of Hofmeister Ions On Solubility And Swelling On Gelatin Hydrogels, Hannah Eldridge

Williams Honors College, Honors Research Projects

Hydrogels are known to be weak and brittle, due to the amounts of water that they hold. Gelatin-based hydrogels specifically are inexpensive and easily accessible, but often have poor physical properties. The goal of my project was to strengthen gelatin-based hydrogels and improve their mechanical properties by forming these hydrogels in different aqueous solutions containing kosmotropic Hofmeister's ions. Prior research has shown that these ions are able to take water away from gelatin-based gels, which forms a tougher hydrogel. The success of this project will be measured by studying the solubility and swelling effects that different Hofmeister ions have on …

A Foundational Approach To Extrusion And Compounding, David Frankart

Williams Honors College, Honors Research Projects

With a history of nearly 200 years, polymer processing and compounding is constantly changing to fit the material science needs of the era. Exposure of undergraduate students to the technology and practices used in industry today in a lab setting would create new opportunities for experiential learning and growth. The objective was to set up a 0.75”, 25 L/D Thermo Haake single screw extruder for lab use and run trials of material in a single screw extruder to set up a basis for experiments. Trials were run of co-polyester resin through a single screw extruder with carbon fiber additives varying …

Controlled Crystallization Of Pet Filaments In Additive Manufacturing, Ryan Kordahi

Williams Honors College, Honors Research Projects

Polyethylene terephthalate (PET) appears in daily life in many forms, the most common being disposable soft drink bottling. To deal with the ever-growing quantitity of disposed PET (both in landfills and environment), a waste plan revolving around depolymerization should be implemented. Specifically, the potential of PET depolymerization through aminolysis into useful, low molecular weight monomers will be explored with the end goal of producing a 3D printing filament and analyzing economic feasibility.