Polymer and Organic Materials Commons^™

Polymer Nanocomposites Containing High Aspect Ratio Particulates: Innovation In Co-Extruded Multilayer Barrier Films, Kevin Meyers

Dissertations

Delaminated montmorillonite (MMT) clay/ maleic anhydride grafted LLDPE nanocomposite multilayer films with alternating layers of LDPE were produced through multilayer co-extrusion. The MMT concentration within the nanocomposite layers was increased through annealing the films in the melt due to a mismatch in interdiffusion rates of the polymer layers. Analysis of the nanocomposite layers upon annealing revealed that the platelets impinged upon one another resulting in significant improvement in oxygen barrier in the multilayer system, exceeding the results of bulk nanocomposites.

Model analysis demonstrated that increasing the nanoplatelet aspect ratio or initial concentration in the filled layers would lead to even …

Highly Flame Retardant And Bio-Based Rigid Polyurethane Foams Derived From Orange Peel Oil, Chunyang Zhang

Electronic Theses & Dissertations

Polyurethane is an important class of polymer which is being used for various industrial applications in the form of rigid foams, flexible foams, thermoplastic, elastomer, coating, and adhesive. Especially there is a huge market for rigid polyurethane foams for their applications as thermal insulating material in building and housing. In general, polyurethanes are prepared using polyols and diisocyanates. Most of the polyols used by industries are petrochemical based. In this project, a novel polyol from an orange peel oil-based derivative, limonene dimercaptan, was synthesized using one step photochemical thiol-ene reaction. The synthesized polyol was used to prepare flame retardant polyurethane …

Review Of Challenges And Advances In Modification Of Food Package Headspace Gases, Ziynet Boz, Bruce A. Welt, Jeffrey K. Brecht, William Pelletier, Eric Mclamore, Gregory A. Kiker, Jason E. Butler

Journal of Applied Packaging Research

Modified Atmosphere Packaging (MAP) has been widely used as an effective way to preserve foods. Fresh produce, meat and meat products, seafood, and dairy products can benefit from modified gaseous atmospheres, which are usually achieved by reducing oxygen and increasing carbon dioxide concentrations, within limits, defined by product tolerances. MAP of fresh produce is particularly challenging because products are living and respiring. Respiration rates depend on several factors including temperature, oxygen, and carbon dioxide concentrations. Balancing package permeation with respiration is challenging, often due to limited selection of practical packaging materials. Failing to remain within tolerance limits of products leads …

Waste Management By Waste: Removal Of Acid Dyes From Wastewaters Of Textile Coloration Using Fish Scales, S M Fijul Kabir

LSU Master's Theses

Removal of hazardous acid dyes by economical process using low-cost bio-sorbents from wool industry wastewaters is of a pressing need, since it causes skin and respiratory diseases and disrupts other environmental components. Fish scales (FS), a by-product of fish industry, a type of solid waste, are usually discarded carelessly resulting in pungent odor and environmental burden. In this research, the FS of black drum (Pogonias cromis) were used for the removal of acid dyes (acid red 1 (AR1), acid blue 45 (AB45) and acid yellow 127 (AY126)) from wool industry wastewaters by absorption process with a view to …

Application Of Cross-Linked Polyborosiloxanes And Organically Modified Boron Silicate Binders In Silicon-Containing Anodes For Lithium-Ion Batteries, Darius A. Shariaty, Dali Qian, Yang-Tse Cheng, Susan A. Odom

Chemistry Faculty Publications

To determine the effect of cross-linking in polymer binders on gravimetric capacity and retention in charge/discharge cycling of lithium-ion batteries containing silicon anodes, polymers with a varied chemiophysical characters have been studied as electrode binders. Here we report the utilization of cross-linked polyborosiloxanes and a boron-modified organosilicate as binders for nanoparticulate silicon-containing anodes for lithium-ion batteries. We show that highly cross-linked binders enable a large degree of capacity to be accessed and that capacity retention is greater when the electrodes are cycled in half cells. More extensive analysis of the boron-modified organosilicate is further explored.

Surface Engineering And Monomer Design For Light-Mediated Ring Opening Metathesis Polymerization, Ishan A. Fursule

Theses and Dissertations--Chemical and Materials Engineering

Stimuli-responsive materials are changing the landscape of actuated materials, optoelectronics, molecular machines, solar cells, temporary memory storage, and biomedical materials. Specifically, photo-responsive polymers have gained acceleration in research and application since the last two decades in the form of a surface coating and micro-patterns. Light as a stimulus can be coherent, mono or polychromatic, tunable for power (intensity) and energy (wavelength), and has precise spatiotemporal control. Conventional surface coating techniques such as spin coating are unable to impart properties to the coatings in terms of sturdiness, homogeneity, uniformity over the complex surface, post deposition modification, and process efficiency. Also, in …

Mixed Matrix Flat Sheet And Hollow Fiber Membranes For Gas Separation Applications, Nicholas W. Linck

Theses and Dissertations--Chemical and Materials Engineering

Mixed matrix membranes (MMM) offer one potential path toward exceeding the Robeson upper bound of selectivity versus permeability for gas separation performance while maintaining the benefits of solution processing. Many inorganic materials, such as zeolites, metal-organic frameworks, or carbon nanotubes, can function as molecular sieves, but as stand-alone membranes are brittle and difficult to manufacture. Incorporating them into a more robust polymeric membrane matrix has the potential to mitigate this issue.

In this work, phase inversion polymer solution processing for the fabrication and testing of asymmetric flat sheet mixed matrix membranes was employed with CVD-derived multiwall carbon nanotubes (MWCNTs) dispersed …

Development Of Starch-Polyvinyl Alcohol (Pva) Biodegradable Film: Effect Of Cross-Linking Agent And Antimicrobials On Film Characteristics, Aniket Satish More, Chandani Sen, Madhusweta Das

Journal of Applied Packaging Research

To satisfy the need of developing eco-friendly flexible antimicrobial packaging film with minimum use of synthetic chemical ingredients, the present study examined the efficacy of citric acid (CA) as cross-linking agent and essential oils (EOs), viz., cinnamon essential oil (CEO) and oregano essential oil (OEO) as natural antimicrobials in corn starch-polyvinyl alcohol (CS-PVA) film. Compared to film prepared from filmogenic solution (FS) containing 75 kg CS+8.75 kg PVA+24.6 kg glycerol per m³ FS, film additionally containing CA at 0.07 kg/kg CS indicated 95% higher ultimate tensile strength (UTS) and 27% lower water vapor permeability (WVP). Film developed with incorporation …

Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, Shahab Kashani Rahimi

Dissertations

Over the past two decades, the increasing concern about the negative environmental impacts of synthetic materials has led to rising interests in utilizing renewable natural resources to develop polymer materials with comparable properties and performance to their synthetic counterparts. One of the major fields of interest is polymer composites where the replacement of synthetic fibers with bio renewable natural fibers is of great potential. However, the processing difficulties, in terms of fiber dispersion and thermal stability have limited the application of cellulosic fibers to polymers with low processing temperatures which are mostly hydrophobic polymers. As a result, the true reinforcing …

Membranes For Food And Bioproduct Processing, Alexandru Marius Avram

Graduate Theses and Dissertations

Modified membranes for process intensification in biomass hydrolysis

Production of biofuels and chemicals from lignocellulosic biomass is one of the leading candidates for replacement of petroleum based fuels and chemicals. However, conversion of lignocellulosic biomass into fuels and chemicals is not cost effective compared to the production of fuels and chemicals from crude oil reserves. Some novel and economically feasible approaches involve the use of ionic liquids as solvents or co-solvents, since these show improved solvation capability of cellulose over simple aqueous systems. Membranes offer unique opportunities for process intensification which involves fractionation of the resulting biomass hydrolysate leading to …

Selective Depolymerization Of Industrial Hemp And Its Effects On Thermal Resistivity, Tanner J. Jolly

Materials Engineering

There is a growing shift within the construction materials industry towards green and sustainable building products. Spending in this area has increased 5 fold since 2011 to a total revenue of $70 billion. An area of particular interest has been aimed at replacing fiberglass batt insulation with cellulose. Cellulose is the most abundant polymer on earth, and has potential to replace petroleum derived insulations. This project explores the potential of selectively isolating cellulose by depolymerizing the support structures found in lignocellulosic materials – specifically lignin and hemicellulose. The current focus is on isolating cellulose from Cannibas sativa, but more …

Polyisobutylene Telechelic Prepolymers By In Situ End-Quenching And Post-Polymerization Modifications, Bin Yang

Dissertations

This volume focuses on the development of telechelic polyisobutylene (PIB) prepolymers by combining end-capping of living carbocationic polymerization of isobutylene (IB) with suitable reactants and post-polymerization modifications. Alkylation kinetics of PIB tert-chloride with alkoxybenzenes using either TiCl₄ or AlCl₃ were investigated. Quantitative para-position end-capped products were only achieved if the alkoxybenzene/AlCl₃ molar ratio was greater than unity; while no such molar ratio is required for TiCl₄, but the alkylation rate was slower than AlCl₃ under the same conditions. Photopolymerization kinetics analysis of PIB triphenol tri(meth)acrylates with low and high M_ns, …

Synthesis And Characterization Of Poly(Simvastatin) - Incorporated Copolymers And Blends For Bone Regeneration, Theodora Asafo-Adjei

Theses and Dissertations--Biomedical Engineering

Common biodegradable polyesters such as poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA) and poly(ε-caprolactone) (PCL) are used as drug delivery vehicles for tissue regenerative applications. However, they are typically bioinert, with drug loading limitations. Polymerizing the active agent or precursor into its respective biodegradable polymer would control drug loading via molar ratios of drug to initiator used for synthesis. Simvastatin was chosen due to its favorable anti-inflammatory, angiogenic, and osteogenic properties. In addition, its lactone ring lends itself to ring-opening polymerization and, consequently, the synthesis of poly(simvastatin) with controlled simvastatin release.

Simvastatin was first polymerized with a 5kDa methyl-terminated poly(ethylene glycol) …

Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra

Theses and Dissertations--Chemical and Materials Engineering

Nano-structured material fabrication using functionalized membranes with polyelectrolytes is a promising research field for water pollution, catalytic and mining applications. These responsive polymers react to external stimuli like temperature, pH, radiation, ionic strength or chemical composition. Such nanomaterials provide novel hybrid properties and can also be self-supported in addition to the membranes.

Polyelectrolytes (as hydrogels) have pH responsiveness. The hydrogel moieties gain or lose protons based on the pH, displaying swelling properties. These responsive materials can be exploited to synthesize metal nanoparticles in situ using their functional groups, or to immobilize other polyelectrolytes and biomolecules. Due to their properties, these …

Design Of Natural Rubber Extraction From Tks Dandelion, Jehad S. Alrawajfeh, Trevor Cody, Jason Pogozelski

Williams Honors College, Honors Research Projects

A design was developed for a controlled environment agriculture 3D greenhouse to grow and harvest TKS dandelions, as well as a processing plant to extract natural rubber and inulin from the roots. The design capacity was scaled for both pilot- and full-scale production: 100 and 100,000 tonnes of natural rubber per year, respectively. The byproducts of the process were dandelion greens, inulin, cellulose, and glucose; all of these except for cellulose were able to be valorized. The greenhouse was designed based on existing 3D hydroponic growing environments, and the extraction process was designed based on the original TKS dandelion extraction …

Fabrication Of Flexible, Biofunctional Architectures From Silk Proteins, Ramendra K. Pal

Theses and Dissertations

Advances in the biomedical field require functional materials and processes that can lead to devices that are biocompatible, and biodegradable while maintaining high performance and mechanical conformability. In this context, a current shift in focus is towards natural polymers as not only the structural but also functional components of such devices. This poses material-specific functionalization and fabrication related questions in the design and fabrication of such systems. Silk protein biopolymers from the silkworm show tremendous promise in this regard due to intrinsic properties: mechanical performance, optical transparency, biocompatibility, biodegradability, processability, and the ability to entrap and stabilize biomolecules. The unique …

Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick

Theses and Dissertations--Chemical and Materials Engineering

Ultrafiltration (UF) processes are often used as pretreatment before more retentive/costly processes, such as nanofiltration and reverse osmosis. This study shows the results of low-biofouling nanocomposite membranes, loaded with casein-coated silver nanoparticles (casein-Ag-NPs). Membranes were cast and imbedded with Ag-NPs using two approaches, physical blending of Ag-NPs in the dope solution (^PAg-NP/CA membranes) and chemical attachment of Ag-NPs to cast membranes (^CAg-NP/CA membranes), to determine their biofouling control properties. The functionalization of Ag-NPs onto the CA membranes was achieved via attachment with functionalized thiol groups with the use of glycidyl methacrylate (GMA) and cysteamine chemistries. The …

Engineering Icephobic Coatings: Surface Characterization Of Pt Cured Silicones, Sithara Shylaja Nair

Theses and Dissertations

Ice buildup on structures leads to problems that include reduced performance, structural damage and power outages. It is therefore important to limit the energy required for removal of ice from substrates to minimize buildup. Understanding the mechanism of ice adhesion and its dependence on variables like coating thickness, stiffness, surface free energy and morphology is critical for minimizing adhesion. Despite several developments in “icephobic” coatings, which are those that have low ice adhesion, it is important to understand adhesion on the fundamental level to make way for advanced coatings. To do so, a study has been carried out that explores …

Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff

Dissertations

The design and synthesis of functional, controlled polymer architectures is essential to the development of new materials with precise and tailorable properties or applications. The work described in this dissertation focuses on the development of controlled polymer architectures with dynamic linkages for the design of multifunctional materials and surfaces via robust, efficient, and stimuli-responsive strategies.

In Chapter III, a post-polymerization modification strategy based on ambient temperature nucleophilic chemical deblocking of polymer scaffolds bearing N-heterocycle blocked isocyanate moieties is reported. Room temperature RAFT polymerization of three azole-N-carboxamide methacrylates, including 3,5-dimethyl pyrazole, imidazole, and 1,2,4-triazole derivatives, afforded reactive polymer scaffolds …

Nanostructured Morphologies In Glassy Polymer Networks, Brian Greenhoe

Dissertations

The body of this work describes a novel approach for the dispersion of multi-walled carbon nanotubes in a high T_g epoxy prepolymer matrix using a twin screw high-shear continuous reactor. The method demonstrated improves on previous dispersion methods in several ways. It offers increased efficiency through excellent heat transfer, while being solvent-less, scale-able, and tailorable to drive dispersion states to judiciously chosen dispersion states. Furthermore, it was shown that dispersion state and agglomerate morphology can be directed, in several ways, through processing conditions and also by controlling the matrix viscosity profile through cure. Broadband dielectric spectroscopy, optical hot-stage microscopy, …

Plasticized Polymer Coatings For Sh-Saw Sensors For High Sensitivity And Long-Term Monitoring Of Btex Analytes In Liquid Phase, Pintu Adhikari

Master's Theses (2009 -)

BTEX compounds (benzene, toluene, ethylbenzene, and xylene) are constituents of crude oil and hazardous to human health. Among them, benzene has the lowest maximum contaminant level for drinking water because of its carcinogenicity. Spills or leakage from underground storage tanks or hazardous waste sites can contaminate nearby groundwater with these volatile organic compounds. Therefore, it is very important to detect the presence of BTEX contamination as early as possible in order to start the remediation process and maintain a healthy environment. To develop an in-situ continuous monitoring sensor system, shear horizontal surface acoustic wave (SH-SAW) sensor devices are being investigated …

Film Performance Of Poly(Lactic Acid) Blends For Packaging Applications, Carlos A. Diaz, Hsunpao Y. Pao, Sungyoung Kim

Journal of Applied Packaging Research

Poly(lactic acid) (PLA), a biodegradable thermoplastic derived from renewable resources, stands out as a substitute to petroleum-based plastics. PLA based films for food packaging has been an area of both commercial and research interest within the context of sustainability. In spite of its high strength, packaging applications have been limited because PLA is more brittle than traditional oil-based plastics. Because of this, films display low tear and impact resistance and produce a loud crackling sound when manipulated. Although many studies address the toughening of PLA in the bulk, little attention has been placed on the film performance. The present study …

Occurrence Of Reverse Side Effects In Corona Treatment Of Dispersion-Coated Paperboard And Its Influence On Grease Barrier Properties, Sami-Seppo Ovaska, Ringaudas Rinkunas, Tadeusz Lozovksi, Robertas Maldzius, Jonas Sidaravicius, Leena-Sisko Johansson, Monika Österberg, Kaj Backfolk

Journal of Applied Packaging Research

The uncoated side of dispersion-barrier-coated paperboards was exposed to positive and negative direct current corona treatments in order to confirm the occurrence of backside treatment and clarify its effects on the usability of the paperboard. The main component of the coating dispersions was hydroxypropylated potato starch and the effects of talc and styrene-butadiene latex additions on backside treatment were evaluated. Coatings with a high talc proportion showed excellent initial grease resistance, but corona-induced strikethroughs caused a drastic decrease in grease penetration time. The root-mean-square roughness measurements revealed moderate surface roughening at the backside, indicating thus backside treatment. The alterations in …

Biopolymeric Mucin And Synthetic Polymer Analogs: Their Structure, Function And Role In Biomedical Applications, Sundar Prasanth Authimoolam, Thomas D. Dziubla

Chemical and Materials Engineering Faculty Publications

Mucin networks are viscoelastic fibrillar aggregates formed through the complex self-association of biopolymeric glycoprotein chains. The networks form a lubricious, hydrated protective shield along epithelial regions within the human body. The critical role played by mucin networks in impacting the transport properties of biofunctional molecules (e.g., biogenic molecules, probes, nanoparticles), and its effect on bioavailability are well described in the literature. An alternate perspective is provided in this paper, presenting mucin’s complex network structure, and its interdependent functional characteristics in human physiology. We highlight the recent advances that were achieved through the use of mucin in diverse areas of bioengineering …

Bioluminescent Magnetic Nanoparticles As Potential Imaging Agents For Mammalian Spermatozoa, Erick Salvador Vasquez, Jean M. Feugang, Scott T. Willard, Peter L. Ryan, Keisha B. Walters

Chemical and Materials Engineering Faculty Publications

Background: Nanoparticles have emerged as key materials for developing applications in nanomedicine, nanobiotechnology, bioimaging and theranostics. Existing bioimaging technologies include bioluminescent resonance energy transfer-conjugated quantum dots (BRET-QDs). Despite the current use of BRET-QDs for bioimaging, there are strong concerns about QD nanocomposites containing cadmium which exhibits potential cellular toxicity.

Results: In this study, bioluminescent composites comprised of magnetic nanoparticles and firefly luciferase (Photinus pyralis) are examined as potential light-emitting agents for imaging, detection, and tracking mammalian spermatozoa. Characterization was carried out using infrared spectroscopy, TEM and cryo-TEM imaging, and ζ-potential measurements to demonstrate the successful preparation of these nanocomposites. Binding …

Bioactive Poly(Beta-Amino Ester) Biomaterials For Treatment Of Infection And Oxidative Stress, Andrew L. Lakes

Theses and Dissertations--Chemical and Materials Engineering

Polymers have deep roots as drug delivery tools, and are widely used in clinical to private settings. Currently, however, numerous traditional therapies exist which may be improved through use of polymeric biomaterials. Through our work with infectious and oxidative stress disease prevention and treatment, we aimed to develop application driven, enhanced therapies utilizing new classes of polymers synthesized in-house. Applying biodegradable poly(β-amino ester) (PBAE) polymers, covalent-addition of bioactive substrates to these PBAEs avoided certain pitfalls of free-loaded and non-degradable drug delivery systems. Further, through variation of polymer ingredients and conditions, we were able to tune degradation rates, release profiles, cellular …

Synthesis Of Titania Thin Films With Controlled Mesopore Orientation: Nanostructure For Energy Conversion And Storage, Suraj R. Nagpure

Theses and Dissertations--Chemical and Materials Engineering

This dissertation addresses the synthesis mechanism of mesoporous titania thin films with 2D Hexagonal Close Packed (HCP) cylindrical nanopores by an evaporation-induced self-assembly (EISA) method with Pluronic surfactants P123 and F127 as structure directing agents, and their applications in photovoltaics and lithium ion batteries. To provide orthogonal alignment of the pores, surface modification of substrates with crosslinked surfactant has been used to provide a chemically neutral surface. GISAXS studies show not only that aging at 4°C facilitates ordered mesostructure development, but also that aging at this temperature helps to provide orthogonal orientation of the cylindrical micelles which assemble into an …

Hybrid Aryl-Ether-Ketone And Hyperbranched Epoxy Networks, John Misasi

Dissertations

In this dissertation, relationships between chemical structures, cure kinetics and network architectures are correlated to bulk mechanical properties for novel, hybrid epoxy-amine networks. The work is split into two primary sections: the first is the synthesis and characterization of multifunctional glassy networks based on aryl-ether-ketone diamine curatives, while the second is based on the synthesis and characterization of hyperbranched epoxy polymers and their resulting networks.

Three aryl-ether-ketone (AEK) diamines of increasing molecular weights were synthesized and used to cure 4,4’-tetraglycidylether of diaminodiphenylmethane (TGDDM); the resulting networks were compared to 4,4’-diaminodiphenyl sulfone cured TGDDM. Architectural differences were created by varying cure …

Influence Of Carbon Nanofillers On The Curing Kinetics Of Epoxy-Amine Resin, Luigi Vertuccio, Salvatore Russo, Marialuigia Raimondo, Khalid Lafdi, Liberata Guadagno

Chemical and Materials Engineering Faculty Publications

The cure kinetics of an epoxy resin based on the tetrafunctional epoxy precursor N,N′-tetraglycidyl methylene dianiline-(TGMDA) hardened with 4,4-diaminodiphenyl sulfone is investigated. The influence of carbon nanofillers (carbon nanotubes, carbon nanofibers, and graphene based nanoparticles) on the cure kinetic is studied. Kinetic analysis is performed by dynamic and isothermal differential scanning calorimetry (DSC).

In dynamic experiments, the activation energy was computed using an advanced isoconversional method while under isothermal conditions, the Kamal’s model of diffusion control was applied to simulate the systems throughout the curing process. The isothermal analysis shows that the introduction of the diluent decreases, …

Synthesis, Characterization, And Thermoelectric Properties Of Radical Siloxanes, Arnold J. Eng, Bryan Boudouris, Edward P. Tomlinson, Martha Emily Hay

The Summer Undergraduate Research Fellowship (SURF) Symposium

More than half of the annual energy consumption in the United States is lost as waste heat. Polymer-based thermoelectric devices have the potential to utilize this waste heat both sustainably and cost-effectively. Although conjugated polymers currently dominate research in organic thermoelectrics, the potential of using polymers with radical pendant groups have yet to be realized. These polymers have been found to be as conductive as pristine (i.e., not doped) poly(3-hexylthiophene) (P3HT), a commonly-used charge-transporting conjugated polymer. This could yield promising avenues for thermoelectric material design as radical polymers are more synthetically tunable and are hypothesized to have a high Seebeck …