Materials Science and Engineering Commons^™

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, …

Insect Antennae As Bioinspirational Superstrong Fiber-Based Microfluidics, Griffin J. Donley

All Theses

Nature is frequently turned to for inspiration for the creation of new materials. Insect antennae are hollow, blood-filled fibers with complex shape, and are cantilevered at the head. The antenna is muscle-free, but the insect can controllably flex, twist, and maneuver it laterally. To explain this behavior, a comparative study of structural and tensile properties of the antennae of Periplaneta americana (American cockroach), Manduca sexta (Carolina hawkmoth), and Vanessa cardui (painted lady butterfly) was performed. These antennae demonstrate a range of distinguishable tensile properties, responding either as brittle fibers (Manduca sexta) or strain-adaptive fibers that stiffen when stretched (Vanessa cardui …

Mechanochromic Tunable Emissions Of Hydrogel Encapsulated Radioluminescent Crystalline Colloidal Arrays, Sarah Mell

All Theses

Crystalline colloidal arrays (CCAs) are periodic dielectric arrays composed of monodisperse, negatively charged nanoparticles with unique optical characteristics. Poly(styrene-co-propargyl acrylate) (PS-PA) based copolymer nanoparticles synthesized via an emulsion polymerization form the basis of the CCAs in this work. The negatively charged surfaces result in the colloidal nanoparticles self-assembling into a face-centered cubic (fcc) crystal-like structure. The long-range order and spatial periodicity of the array result in a rejection wavelength, characteristic of CCAs, in which a specific wavelength of light is forbidden from propagating throughout the optical system. The CCAs exhibit mechanochromism through a rejection wavelength shift corresponding to a change …

Additive Manufacturing Of Variable Contrast Computed Tomography Anatomical Phantoms Using A Single Feedstock In Fused Filament Fabrication, Cory J. Darling

LSU New Orleans Theses and Dissertations

Anatomical phantoms used in biomedical education and training benefit greatly from Fused filament fabrication’s (FFF) ability to rapidly produce complex and unique models. Current materials and methods used in FFF have limited ability to accurately produce phantoms that can mimic the radiological properties of multiple biological tissues. This research demonstrates that the CT contrast of FFF produced models can be modified by varying the concentration of bismuth oxide in acrylonitrile butadiene styrene (ABS) filaments and a tunable CT contrast that mimics the CT contrast ranging from fatty tissue to cortical bone using a single composite filament without introducing artificial image …

Synthesis Of Monodisperse Nanoscintillators At High Temperatures For Biomedical Relevant Applications, Eric Zhang

All Dissertations

Luminescent sub-100 nm particulates continuously generate immense research interest in the biomedical field for imaging, theranostics, and optogenetics. Conventionally, upconversion nanoparticles or UV activated semiconductors are studied, however these materials are limited by biological barriers such as the skin which reduces the penetration depth of these excitation sources, tissue's auto- fluorescence, and toxicity. One approach to overcome these challenges is to use nanoscintillators (sub-100 nm materials that can generate visible light using high energy excitation sources such as x-rays) which can generate light locally to the human body. Numerous scintillators have been reported since the discovery of x-rays from the …

Synthesis And Molecular Processes Governing Self-Healing Polymeric Materials, Siyang Wang

All Dissertations

Self-healing polymers capable of recovering from physical damages are promising materials for advanced technologies. In these studies, we developed routes to achieve self-healable properties in acrylic-based copolymers that rely on non-covalent dipolar interactions present in essentially all polymeric materials. Using a combination of spectroscopic tools, thermo-mechanical analysis, and molecular dynamic (MD) simulations, these studies have shown that dipolar interactions lead to conformational changes of macromolecular segments which, in turn, result in self-healing without external intervention. This dissertation also describes the development of novel self-healable acrylic-based covalent adaptable networks (CANs) that combine reprocessing and self-healing properties. The utilization of dipolar interactions …

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 …

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 …

Sustainable Composites From Agricultural And Petroleum Waste, Menisha S. Karunarathna

All Dissertations

Green gas emission has been a pervasive and persistent subject of debate for a prolonged period. The soaring number of industries and vehicle fuel emissions presage a concomitant rise in global CO₂ emissions. Global cement production is responsible for 8% of the total CO₂ release, yet, the production continues due to the surging demand. Hence, there is an ongoing quest to find alternatives for cement and building materials produced with zero to lower CO₂ emissions. The work presented in this dissertation focuses on finding recyclable, zero CO₂ gas-producing high sulfur biocomposites materials, which can compete with …

Effects Of Sizing Agents On Mechanical Properties Of Carbon Fiber–Polymer Composites Via Fused Filament Fabrication Additive Manufacturing., Benjamin D. Mitchell

Electronic Theses and Dissertations

This study demonstrated the effects of changing the sizing agent parameter during the preparation of carbon fibers on the mechanical properties of composite made with acrylonitrile butadiene styrene (ABS) as the matrix material and carbon fibers as the fiber material. Three types of sizing agents produced by Allnex were used to coat three different batches of carbon fibers that were mixed with a torque rheometer and extruded with a barrel-style melt extruder into continuous spools of 1.75 mm filament for use with commercial 3D printers. Tensile tests were conducted on the filaments and tensile bars printed from the materials. Results …

Simplified Synthesis Of Conjugated Polymers Enabled Via 1,4-Dihydropyrrolo[3,2-B]Pyrrole, Kenneth-John Jack Bell

Master of Science in Chemical Sciences Theses

Conjugated polymers have attracted significant attention as the active layer material in organic electronics, such as organic photovoltaics and light-emitting diodes, partly due to the ability to influence a broad range of properties through structural design motifs. However, high performance conjugated polymers suffer from numerous synthetic steps, generation of toxic waste, and harsh reaction conditions all of which impart additional costs that inhibit their widespread utilization. Therefore, an emphasis on reducing synthetic complexity and utilizing abundant, commercially available starting materials is needed for organic electronics to reach their full potential. Dihydropyrrolo[3,2-b]pyrrole (H₂DPP) chromophores offer a simple one-pot synthesis …

Detection Of Trace Heavy Metals In Water: Development Of Electrochemical Sensors, Quang Lam, Joel Mututeke

Symposium of Student Scholars

The presence of heavy metals in our ecosystem poses significant ecological and physiological consequences. As a result, numerous techniques are developed for the detection of contaminants in aqueous solutions. However, early and trace detection of such contaminants still remains a challenge. Amongst many techniques, electrochemistry driven sensors have shown promise due to their possibility of miniaturization and low-cost. Our research investigates the use of electrically conducting polymer and atomically thin carbon materials as electrodes towards the development of electrochemical sensor. Nanocomposite electrode films have been synthesized and fabricated using in-situ polymerization technique and the relationship between number of cycles of …

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 …

Prospects For Using Metal-Polymer Composite Structures In The Gear Manufacturing, Umid Mamasobirov, Shoraxmat Shoobidov, A F. Husanboyev

Technical science and innovation

In this paper, some thermoplastic polymer composites and filler composites for the production of metal-polymer gear transmissions are presented. Efforts have been made to expand the raw material base and identify ways to increase the durability of gears through technological and design measures.

Machine Learning Assisted Discovery Of Shape Memory Polymers And Their Thermomechanical Modeling, Cheng Yan

LSU Doctoral Dissertations

As a new class of smart materials, shape memory polymer (SMP) is gaining great attention in both academia and industry. One challenge is that the chemical space is huge, while the human intelligence is limited, so that discovery of new SMPs becomes more and more difficult. In this dissertation, by adopting a series of machine learning (ML) methods, two frameworks are established for discovering new thermoset shape memory polymers (TSMPs). Specifically, one of them is performed by a combination of four methods, i.e., the most recently proposed linear notation BigSMILES, supplementing existing dataset by reasonable approximation, a mixed dimension (1D …

Polyaniline/Cobalt Nanoparticle Composite Films, Rifat Mahbub

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Polymer nanocomposites have been gaining attention because of the enhanced properties of the element materials it can offer. These composites have been used in biological sector as well as quantum computing and memory devices. These are also used as different kind of sensors. Polymer composites incorporated with magnetic nanoparticles can modify the magnetic property of the nanoparticles and that has huge potential to be used in different sort of applications.

This work aims to develop a polymeric nanocomposite incorporating a conducting polymer and magnetic nanoparticles. The influence of the conducting polymer on the magnetic property of the nanoparticles was investigated. …

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 …

Thermomechanics Of Semiconducting Polymers And Their Morphological Phenomena, Luke Galuska

Dissertations

In contrast to conventional silicon-based electronics, semiconducting polymers show great promise for emerging applications in soft, flexible, and ductile electronic technologies. This is due to their polymeric nature, tailorable structure, and sub-100 nm device thickness. Despite this mechanical novelty, there remains a poor understanding of their structure-property-processing relationships, which has hindered growth within the field. This dissertation elucidates these relationships through investigation of their thermomechanics, and morphological phenomena. This was accomplished through the following projects:

1) To demonstrate the impact of backbone rigidity on semiconducting polymer thermomechanics, we varied the backbone rigidity of an NDI-based polymer by inserting flexible methylene …

Optimization Of A Novel Nipam-Based Thermoresponsive Copolymer For Intramuscular Injection As A Myoblast Delivery Vehicle To Combat Peripheral Artery Occlusive Disease, Quentin R. Klueter

Master's Theses

There is a need for a minimally invasive delivery method to enable cell therapies to combat peripheral artery occlusive disease (PAOD) in end stage patients. Myoblasts show promise as a cell mediated therapy but warrant an improved delivery method to increase cell retention in the region of interest because of their adherent nature, relative to previously used BM-MNC’s that are non-adherent. Contemporary issues with achieving successful cell therapies of vasculature can be mainly characterized by the lack of clinical translation from promising animal studies and absence of cell delivery scaffolding. Naturally, polymers have been widely experimented with as grafts to …

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, …

Study Of Various Quality Characteristics Of Polyester Fibers Obtained On The Basis Of Primary And Secondary Polyethylene Terephthalate, Samida Ernzarova, Asror Juraev, Muzaffar Alimukhamedov, Farhod Magrupov

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of study is comprehensive determination of various quality characteristics of polyester fibers obtained on the basis of primary and secondary polyethylene terephthalate. The analysis of the raw material base of pre-oriented yarns (POY) threads has been carried out. The technological, physicomechanical properties, as well as the structure of the primary and secondary polyethylene terephthalate used in the production of the threads have been studied. The structure and properties of polyethylene terephthalate changed: the properties were worse, the structure were amorphous, the molecular weight decreased. The structure of recycled polyethylene terephthalate changed as a result of technological conversions in …

Мulti-Layer Fibrous Material Based On Textile Waste, Sevara Alimkhanova, Nodir Mirzaev, Adham Rafikov

CHEMISTRY AND CHEMICAL ENGINEERING

At the textile and sewing and knitting enterprises of the Republic of Uzbekistan, the number of which increases every year, a sufficient amount of technological waste is accumulated, which formed in the processes of sizing yarn, starting and setting up equipment, designing and sewing products. Meanwhile, there is a shortage of warm, comfortable, light, soft lining materials for clothes and shoes based on natural raw materials. With the purpose of rational use of textile waste - shredded, disheveled scraps of fabric and knitwear, a multilayer nonwoven material for details of clothing and footwear has been obtained. The material formed by …

Spectral Features And Hydrogen Bond Structure Of Aqueous Solutions Of Ethanol, Dilbar Bozorova, Shukur Gofurov, Mavlonbek Ziyayev, Abdulmutallib Kokhkharov, Oksana Ismailova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is develop an approach that makes it possible to study the spectral properties and structure of intermolecular hydrogen bonds in aqueous solutions of ethanol formed in systems whose existence in a gaseous medium or an isolated state is practically impossible. This approach bases on the combined use of infrared spectroscopy and molecular dynamics (MD) methods. An analysis give the structural reorganization of water molecules depending on the concentration of ethanol alcohol. It has been shown that the method of molecular dynamics with classical force fields makes it possible to explicitly take into account the molecules …

Determination Of The Stability Of Complex Compounds Of Copper (Ii), Zinc (Ii), Cadmium (Ii) And Silver (I) With Covalently Immobilized Sulfur Contain Ligands, Sherzod Kasimov, Khayit Turaev, Abdulakhat Jalilov, Farkhod Narmuratov, Zulkhumor Jumayeva

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this study is to determine the stability of the obtained coordination compounds of some d-metals with covalent immobilized sulfur-containing ligands. To achieve this goal, coordination compounds of copper (II), zinc (II), cadmium (II) and silver (I) ions with covalent immobilized sulfur-containing ligands - О,О-di- (2-aminoethyl) -dithiophosphate potassium - polyester matrix (KD2AEDTP-PEM), O,O-di- (2-aminoethyl) -dithiophosphate potassium - carbamide-formaldehyde matrix (KD2AEDTP-KFM). Studies were carried out to determine the acid-base properties of covalent-immobilized sulfur-containing ligands - KD2AEDTP-PEM, KD2AEDTP-KFM and the concentration stability of the obtained coordination compounds with ions of copper (II), zinc (II), cadmium (II), and silver (I). Based …

Synthesis And Spectroscopic Study Of Complex Compounds Mn(Ii), Co(Ii), Cu(Ii) And Zn With 5-Amino-2-Mercaptobenzimidazole, Lobar Gapurova, Dilnoza Rakhmonova, Shakhnoza Kadirova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this work is to study the effect of the nature of electron-donor and electron-withdrawing substituents in the molecules of heterocyclic ligands, the nature of acidoligands and transition metal ions on the properties of the synthesized coordination compounds. A method for the synthesis of new complex compounds of Mn (II), Cо (II), Cu (II) and Zn with 5-amino-2-mercaptobenzimidazole has been developed and the composition and structure of the synthesized complex compounds have been studied using modern physicochemical methods, such as elemental, thermogravimetric, X-ray phase analysis and IR spectroscopy. Coordination competing donor centers, electronic and geometric structures of the …

Influence Of Pinholes On Water Vapor And Oxygen Permeation Of Packaging Foil And Films, Petri Johansson, Johanna Lahti, Jurkka Kuusipalo

Journal of Applied Packaging Research

Controlling of moisture and oxygen permeation through the packaging material is essential in most packaging applications. With multilayer structures of different barrier materials, there is possibility to create desired barrier properties to the package. The challenge is to plan appropriate barrier level, e.g. WVTR and OTR, theoretically to the package before producing the package. Furthermore, in specific packages there is a need to control the permeation e.g. respiration in vegetable packages. Typically foils and polymer films have high barrier properties, therefore, permeation can be controlled by producing artificial pinholes in these kinds of packages.

Influence of artificial pinholes in aluminium …

Monitoring Of State Transitions In Extreme Environment Application Materials Using Fiber Bragg Grating Sensors, Sabuj Khadka

Electronic Theses and Dissertations

By embedding both a single fiber Bragg grating (FBG) sensor and a thermocouple (TC) during the manufacturing for extreme environment applications of certain classes of materials such as metals and polymers, a novel in-situ approach was developed to precisely monitor their entire manufacturing processes. This novel monitoring technique was able to identify many characteristic points during the curing of room and high-temperature epoxies and the solidification processes of metal alloys composed of tin and bismuth which were selected in this research purely for verification purposes. Some of the characteristic points identified for the epoxies were: (i) the gel point, (ii) …

Carbon Nanotube Coated Fibrous Tubes For Highly Stretchable Strain Sensors Having High Linearity, Chenchen Li, Bangze Zhou, Yanfen Zhou, Jianwei Ma, Fenglei Zhou, Shaojuan Chen, Stephen Jerrams, Liang Jiang

Articles

Strain sensors are currently limited by an inability to operate over large deformations or to exhibit linear responses to strain. Producing strain sensors meeting these criteria remains a particularly difficult challenge. In this work, the fabrication of a highly flexible strain sensor based on electrospun thermoplastic polyurethane (TPU) fibrous tubes comprising wavy and oriented fibers coated with carboxylated multiwall carbon nanotubes (CNTs) is described. By combining spraying and ultrasonic-assisted deposition, the number of CNTs deposited on the electrospun TPU fibrous tube could reach 12 wt%, which can potentially lead to the formation of an excellent conductive network with high conductivity …

Additive Manufacturing Waste Management System - Plastic Extrusion Process, Gabriel Bennett, Lindsay Liebrecht, David Lyogky, Wilson Woods

Williams Honors College, Honors Research Projects

3D printing is a fast-growing market with its main source of waste being PLA and ABS plastics. In 2019, the global additive manufacturing market grew to over $10.4 billion, crossing the pivotal double-digit billion threshold for the first time in its nearly 40-year history. (SmarTech Analysis, 2020 Additive Manufacturing Market Outlook and Summary of Opportunities Report). The waste is generated from failed prints and rejected support structures which are common occurrences for personal use. Plastic recycling has become one of the leading discussions of environmental protection and waste management. The 3D market currently does not offer an effective and affordable …

Influence Of Saturation Nonequilibrium And Variable Operation Conditions On The Electromechanical Performance Of Ionic Polymer Metal Composite Actuator Architectures, Allison Maria Arnold

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electroactive polymers (EAPs) continue to gain attention for their potential to offer unique and versatile solutions in the soft robotic and flexible electronic industries. Ionic Polymer-Metal Composites (IPMCs) are a class of ionic-type EAPs which can be configured as capacitor actuators with very low voltage requirements (≤ 5 V AC or DC). Their compact, portable, and lightweight properties, coupled with a biomimetic bending actuation response make them ideal for human-machine integrated technologies such as medical implants, active skins, and artificial muscles. The Nafion-based IPMC can be described as a layered composite capacitor containing an ionic polymer core, sandwiched between chemically …