Polymer Science Commons^™

Carbon Fibers From Bio-Based Precursors Derived From Renewable Sources, Sagar Kanhere

All Dissertations

Carbon fibers have the highest strength and modulus among all known fibers and are used as reinforcements in high-performance composites [1]. Carbon fibers also have a very low density relative to metals. Therefore, carbon fibers possess ultrahigh specific strength and modulus, which make them desirable for high-performance light-weight composites. A vast majority of commercial carbon fibers are produced from PAN precursors that are expensive, which limits the use of PAN-derived carbon fibers to aerospace applications (e.g., airplanes). However, for costsensitive applications, there is a need for low-cost, moderate performance carbon fibers. Lignin is a low-cost by-product of pulping and biorefining …

Sustainable Material For Urea Delivery Based On Chitosan Cross-Linked By Glutaraldehyde Saturated Toluene: Characterization And Determination Of The Release Rate Mathematical Model, Jayanudin Jayanudin, Retno S. D. Lestari, Indar Kustiningsih, Dandi Irawanto, Rozak Rozak, Reyonaldo L. A. Wardana, Fakhri Muhammad

Karbala International Journal of Modern Science

The aims of this study were to characterize the urea-loaded chitosan microspheres and determine the release kinetic constants and diffusion coefficients. An emulsion cross-linking method was used to prepare the urea-loaded chitosan microspheres. Urea was dissolved in a solution of chitosan then put into vegetable oil and stirred to form an emulsion. Glutaraldehyde saturated toluene (GST) was added into the emulsion dropwise while continuously stirring for the solidification process. Chitosan microspheres filled with urea were washed, dried, and then analyzed. Characterization of the urea-loaded chitosan microspheres was conducted using a scanning electron microscope (SEM), Raman spectroscopy, X-ray diffraction, and particle …

Receptor-Doped Organic Transistors: Transducing Anion Binding From Mixed Ionic-Electronic Transport, Anthony Benasco

Dissertations

Organic semiconductors based on π-conjugated polymers show remarkable properties such as high tolerance to structural defects, low processing temperature requirements, biocompatibility, ease of fabrication, and tunable properties. Conjugated polymers integrated into device arrays can exhibit collective properties sensitive to minor perturbations in the surrounding media. However, these devices rely on serendipitous sensitivity to the analyte of interest, and strategies for specific detection remain a considerable change. There remains a compelling, global need for technologies to monitor phosphate due to its prevalence in agricultural runoff, leading to fish kills and economic decline for commercial and recreational fisheries. The strong hydration energies …

Reactive Thin Film Polymers And Thin Film Composite Membranes For The Rapid Screening Of Uranium Isotopes, Abenazer W. Darge

All Dissertations

Traditional radiochemistry approaches for the detection of trace-level alpha-emitting radioisotopes in water require lengthy offsite sample preparations and do not lend themselves to rapid quantification. Therefore, a novel platform is needed that combines onsite purification, concentration, and isotopic screening with a fieldable detection system. My dissertation research objective was to develop novel reactive thin polymer films and thin film composite membranes for the selective separation of uranium from environmental water followed by direct isotopic analysis by alpha spectroscopy. Chapter 1 reviews progress made on uranium separation from aqueous matrices and discusses methods used for the determination of isotopic composition.

Chapter …

Isolation And Production Of Tandem Collagen Binding Domain From Clostridial Collagenase Colg And Developments In C1q Reagent Production For Future Molecule Characterization Work, Stephanie Beitle

Chemical Engineering Undergraduate Honors Theses

This thesis covers a two part project: the production methods to create a double collagen binding domain molecule with a growth factor for wound healing applications and the development of a new in-house production method for isolating C1q from bovine blood. The wound healing molecule was created using transformation, sonication, and purification before being tested via electrophoresis SDS page and Western blots to confirm the molecule’s presence. The C1q in-house production method utilizes an ultrafiltration flow cell rather than dialysis at a critical point in the process, allowing for researchers to not only be able to use a single small …

Synthesis And Phase Transition Characterization Of Liquid Crystal Membranes With Slit-Like Pores, Isaac Hopwood

Chemical Engineering Undergraduate Honors Theses

Membranes with slit-like pores have been of interest for some time due to their ability to reject smaller particles than traditional cylindrical-pored membranes at the same fluid flux. However, using liquid crystals as a template for this sort of membrane has not been thoroughly investigated. In this study, the liquid crystal mixture of RM257 (2-Methyl-1,4-phenylene bis(4-(3-(acryloyloxy)propoxy)benzoate)) and 5CB (4-Cyano-4'-pentylbiphenyl) for the purpose of manufacturing membranes with slit-like pores, the phase transition behavior of this LC mixture at various mole fractions of RM257, and the impact of mole fraction of RM257 in the liquid crystal (LC) mixture and membrane manufacturing conditions …

Investigating The Effect Of Polymer Hydrogels On The Antimicrobial Properties Of Activated Carbon Through The Utilization Of Bacterial, Viral, And Parasitic Microorganisms, Zoe Gunter

Honors Theses

Activated carbon (AC) has long been utilized in biomedical applications due to its innate antimicrobial characteristics. However, little is understood about the mechanism of action that allows AC to prohibit the propagation of different pathogen species. To further ascertain these characteristics and how they affect the propagation of pathogens, procedures were designed with bacterial, viral, and parasitic agents which were utilized in conjunction with varying concentrations of polymer hydrogels to examine the antimicrobial efficacy of AC. The studies performed for this thesis were conducted employing coconut-based AC and Noveon^® AA-1 Polycarbophil USP or Carbopol^® 974P NF hydrogels which, …

Extractive Membranes For The Detection And Screening Of Waterborne Plutonium, James Foster

All Dissertations

The development of rapid screening tools for special nuclear materials remains a crucial focus for nonproliferation efforts. Traditional approaches for the analysis of trace-level Pu isotopes in water requires tedious and time-consuming sample preparation steps that do not lend well to expeditious screening. Therefore, a novel analytical method that combines both Pu concentration and source preparation into a single detection system would make for an invaluable tool for nuclear security applications. Extractive membranes absorbers can help to fulfill this role as they are capable of concentrating Pu to detectable limits while subsequently serving as alpha spectrometry sample sources. In Chapter …

Novel Thermal Coating For High-Speed Airplanes, Abinash Satapathy, Lakshay Battu, Liam Watson, Nazanin Rajabi

Symposium of Student Scholars

In comparison to various other materials, Carbon Fiber, specifically Carbon Fiber Reinforced Polymers (CFRP), is pre-eminent amongst other materials for use on aeronautical systems. Due to its high specific strength (strength-to-weight ratio), CFRP is prominent for carrying heavy loads while maintaining a lightweight build. However, when influenced by heat resulting from air resistance, CFRP is known to undergo serious degradation that would significantly decrease the effectiveness of the polymers. To prevent this degradation and maintain the strength of the CFRP, thermal protective layers (TPLs) are designed to shield the CFRP from heat exposure. This research is focused on the examination …

Tuning Electrochemical Interactions And Polymer Electrolyte Interfaces For Enhanced Organic Acid Separations Using Electrodeionization, Matthew Leo Jordan

LSU Doctoral Dissertations

Chemical separations are critical processes for chemical and industrial plants to purify and isolate products however current separation technologies, such as distillation, rely on energy intensive processes. Electrochemical separation processes, such as electrodialysis and electrodeionization, are an energy efficient alternative that are emerging as an alternative for thermal-based separations. Organic acids are weakly ionizable species and susceptible for purification from process streams using electrochemical processes. Recently the fermentation route has garnered greater attention as a means for producing value-added chemicals, such as organic acids, from a renewable feedstock and aiding the circular economy. Some of the challenges electrodialysis faces for …

4,6-O-Phenylethylidene Acetal Protected D-Glucosamine Carbamate-Based Gelators And Their Applications For Multi-Component Gels, Pooja Sharma, Guijun Wang

Chemistry & Biochemistry Faculty Publications

The self-assembly of carbohydrate-based low molecular weight gelators has led to useful advanced soft materials. The interactions of the gelators with various cations and anions are important in creating novel molecular architectures and expanding the scope of the small molecular gelators. In this study, a series of thirteen new C-2 carbamates of the 4,6-O-phenylethylidene acetalprotected D-glucosamine derivatives has been synthesized and characterized. These compounds are rationally designed from a common sugar template. All carbamates synthesized were found to be efficient gelators and three compounds are also hydrogelators. The resulting gels were characterized using optical microscopy, atomic force microscopy, …

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 …

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 …

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 …

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 …

Optimization In The Application Of Varnishes Barrier On Cartonboard Packaging, Andre Ramalheiro De Andrade, Maria Isabel Rodrigues Phd, Eduardo Luiz Machado Phd

Journal of Applied Packaging Research

In this work adjustments in the rotogravure printing process are proposed to the varnish water vapor transmission rate (WVTR) aiming to obtain results smaller than 20g/m²/24h. One case study was used for the propositions for improvements, where focused on varnish application process in a gravure printer for an eight-printing unit cartonboard packaging, maximum printing speed of 175 m/min and a 285 g/m² weight cartonboard. The possible variables that influenced the WVTR result were selected from the technical expertise of the people involved in the project, the analysis in the printing process with the application of directed trials using experimental designs …

Tools And Strategies For The Patterning Of Bioactive Molecules And Macromolecules, Daniel J. Valles

Dissertations, Theses, and Capstone Projects

Hypersurface Photolithography (HP) is a printing method for fabricating structures and patterns composed of soft materials bound to solid surfaces and with ~1 micrometer resolution in the x, y, and z dimensions. This platform leverages benign, low intensity light to perform photochemical surface reactions with spatial and temporal control of irradiation, and, as a result, is particularly useful for patterning delicate organic and biological material. In particular, surface- initiated controlled radical polymerizations can be leveraged to create arbitrary polymer and block- copolymer brush patterns. Chapter 1 will review the advances in instrumentation architectures from our group that have made these …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Phase-Field Modeling Of The Polymer Membrane Formation Process For Micro- And Ultra-Filtration, Michael Rosario Cervellere

Graduate Theses and Dissertations

Porous polymer membrane filters are widely used in separation and filtration process. Micro- and ultra-filtration membranes are commonly used in biopharmaceutical applications such as filtering viruses and separating proteins from a carrier solution. The formation of these membrane filters via phase inversion is a complex and interconnected process where varying casting conditions can have a wide variety of effects on the final membrane morphol- ogy. Tailoring membrane filters for specific performance characteristics is a tedious and time consuming process. The time and length scales of membrane formation make it extremely difficult to experimentally observe membrane formation. Modeling the membrane formation …

Investigation Of Membrane Based Processes For Biomedical Applications, Efecan Pakkaner

Graduate Theses and Dissertations

As substantial developments were achieved in nanotechnology and polymer engineering, especially in the last few decades, the use of membranes and membrane-based procedures was found to be expanding into more and more research and development areas; including biological engineering, life sciences and biomedical engineering. Not only have they been the main focus of meaningful research, but they have also been the main pieces of the solutions to very thorny problems encountered within a wide range of applications from microfluidics to water treatment, thanks to their versatility, cost-effectiveness and biocompatibility, when compared to conventional separation techniques. To celebrate and embrace these …

High Performance Mixed-Matrix Electrospun Membranes For Ammonium Removal From Wastewaters, Shu-Ting Chen, Sumith Ranil Wickramasinghe, Xianghong Qian

Chemical Engineering Faculty Publications and Presentations

Mixed-matrix electrospun membranes were developed to investigate ammonium removal from low ammonium concentration wastewaters for the first time. Particles derived from the inexpensive zeolite 13X were successfully incorporated into polyethersulfone (PES) matrices. The fabricated mixed-matrix electrospun membranes demonstrate high ammonium removal capacity reaching over 55 mg/g_zeolite, more than 2.5 times higher than the previously fabricated mixed-matrix membranes via non-solvent induced phase inversion. Moreover, the membranes fabricated exhibit high permeability and ease of regeneration. Over 90% of total ammonium nitrogen (TAN) can be removed from low TAN wastewaters such as aquaculture wastewaters. In addition to zeolite 13X, other zeolite …

Biopolymeric Materials For Tissue Regeneration, Cell Manufacturing, And Drug Delivery, David Alfonso Castilla-Casadiego

Graduate Theses and Dissertations

The development of materials for tissue regeneration, cell manufacturing, and drug delivery is possible by the manipulation of polymer properties and the use of three different techniques including layer-by-layer, electrospinning, and molding technique.

By applying the layer-by-layer technique over biomaterials, it is possible to develop polymeric multilayers that promote a more favorable environment for cellular functionality, increasing the possibility of improving their acceptance in the area of implantation. IRVASE demonstrated being a powerful technique that allows for a reliable characterization of the physical-chemical and thermal properties of the fabricated surfaces. This opens the possibility to monitor the design of surfaces …

Peptoid-Based Microsphere Coatings For Biomaterial Applications, Jesse Leland Roberts

Graduate Theses and Dissertations

Peptoids are peptidomimetic oligomers that predominantly harness similarities to peptides for biomimetic functionality. The incorporation of chiral, aromatic side chains in the peptoid sequence allows for the formation of distinct secondary structures and self-assembly into supramolecular assemblies, including microspheres. Peptoid microspheres can be coated onto substrates for potential use in biosensor technologies, tissue engineering platforms, and drug-delivery systems. They have the potential for use in biomedical applications due to their resistance to proteolytic degradation and low immunogenicity. This dissertation focuses on the physical characteristics and robustness of the peptoid microsphere coatings in various physiological conditions, along with their ability to …

Husky Hand: A Low-Cost Electro-Mechanical Prosthetic Arm For The Underprivileged, Adam Robert

Thinking Matters Symposium

A continuation of a low-cost prosthetic upper limb prototype design which was investigated in EGN 301. The prosthetic is specifically designed for the needs and requirements of under privileged individuals in the Dominican Republic with upper limb amputations. The project focuses on the creation of an open-source computer aided prosthetic hand/arm model. The design allows consumer-grade fused filament fabrication (FFF) 3-D printers to be used. The improved design allows for the integration of the PQ-12 linear actuator for grasp and finger control. This simplifies the assembly, while, also reducing the size and mass of the whole unit. Producing a low-cost …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Nature-Inspired Material Strategies Towards Functional Devices, Sayantan Pradhan

Theses and Dissertations

Naturally sourced, renewable biomaterials possess outstanding advantages for a multitude of biomedical applications owing to their biodegradability, biocompatibility, and excellent mechanical properties. Of interest in this dissertation are silk (protein) and chitin (polysaccharide) biopolymers for the fabrication of functional biodevices. One of the major challenges restricting these materials beyond their traditional usage as passive substrate materials is the ability to combine them with high-resolution fabrication techniques. Initial research work is directed towards the fabrication of micropatterned, flexible 2D substrates of silk fibroin and chitin using bench-top photolithographic techniques. Research is focused on imparting electrochemical properties to silk proteins using conducting …

Applied Machine Learning In Extrusion-Based Bioprinting, Shuyu Tian

Theses and Dissertations

Optimization of extrusion-based bioprinting (EBB) parameters have been systematically conducted through experimentation. However, the process is time and resource-intensive and not easily translatable across different laboratories. A machine learning (ML) approach to EBB parameter optimization can accelerate this process for laboratories across the field through training using data collected from published literature. In this work, regression-based and classification-based ML models were investigated for their abilities to predict printing outcomes of cell viability and filament diameter for cell-containing alginate and gelatin composite hydrogels. Regression-based models were investigated for their ability to predict suitable extrusion pressure given desired cell viability when keeping …

Development Of An Injectable Methylcellulose Hydrogel System For Nucleus Pulposus Repair And Regeneration, Nada A. Haq-Siddiqi

Dissertations and Theses

Low back pain is the most common cause of disability in the world and is often caused by degeneration or injury of the intervertebral disc (IVD). The IVD is a complex, fibrocartilaginous tissue that allows for the wide range of spinal mobility. Disc degeneration is a progressive condition believed to begin in the central, gelatinous nucleus pulposus (NP) region of the tissue, for which there are few preventative therapies. Current therapeutic strategies include pain management and exercise, or surgical intervention such as spinal fusion, none of which address the underlying cause of degeneration. With an increasingly aging population, the socioeconomic …

Determination Of Hydrogel Degradation By Passive Mechanical Testing, Avery Rosh-Gorsky

Honors Theses

This paper details a new technique to measure the mechanical properties of ETTMP PEGDA hydrogels using Hertz Contact Theory and simultaneously analyze both the model drug release and gel erosion in situ. This method involves curing a drug loaded hydrogel in a standard cuvette and placing a glass bead and phosphate buffer solution (PBS). Over time, the cross-linked network of the hydrogel breaks down, and, as a result, the ball sinks into the hydrogel. This method provides a macroscopic and inexpensive way to continuously and passively measure properties of the hydrogel as the hydrogel degrades. By plotting both the …

Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin

Master’s Theses

Polymer gels can be used in the fabrication of materials for filtering liquid and gaseous media, solid-state electrolytes, and transdermal medical patches. This diverse range of applications primarily relies on the transport and mechanical properties of polymer gels. Both sets of properties have shown excellent tunability, but typically in a coupled fashion. Establishing the independent tunability of the transport and mechanical properties of polymer gels (using simple, cost-effective methods) is paramount if polymer gels are to be used to their full potential. Specifically, block copolymer gels self-assemble into organized nanoscale networks within the gel solvent, which allows for facile control …