Polymer and Organic Materials Commons^™

Enhanced Performance Of 3d Electroactive Polymer Transducers Via Hierarchical Structures, Frederick B. Holness

Electronic Thesis and Dissertation Repository

Conjugated polymers (CPs) are a class of polymers that exhibit a change in size or shape in response to electrical stimuli. The unique combination of electrical and mechanical properties facilitates the fabrication of novel devices in a broad range of applications including: sensors, actuators, and lab-on-a-chip systems. The alternating single and double bonds along the polymer chain of CPs enables their electroactive properties but is also responsible for processability associated with CPs that has limited fabrication methods. Recently a photosensitive CP composite enabling additive manufacturing (AM) of 3D CP structures was developed. However, the introduction of a copolymer for mechanical …

Nanocomposites For Applications In Ultracapacitors Based Energy Storage Systems, Duy Pham, Jake Ivirn, Jacob Dileonardi, Ben Mckinney, Ashish Aphale

Symposium of Student Scholars

Electrochemical capacitors also known as ultracapacitor is a potential technology for modern energy storage due to their high performance of charge capacity and fast charge-discharge rates. The superior performance of ultracapacitors will help to meet demands for energy systems in applications such as transportation. Ultracapacitor device consists of electrodes, a polymeric separator, and an electrolyte. Under the applied voltage, the migration of ions between two porous electrodes from the bulk of the electrolyte governs the performance of such devices. In this work, we present experimental research on the synthesis of different electrode materials using atomically thick graphene and conducting polymers. …

Development Of Electrochemical Sensors For The Detection Of Trace Contaminants, Quang Lam, Ashish Aphale, Duy Pham

Symposium of Student Scholars

Several industrial processes, such as stainless steel fabrication and textiles, produce heavy metal byproducts such as chromium. These heavy metals have detrimental effects on the surrounding environments and humans. Recently, electrochemical-driven sensors have been studied and show great potential in miniaturization while still providing measurements at a low cost. In addition, atomically thin allotropes of carbon, graphene, and graphene oxide have shown remarkable results in producing a highly responsive and selective sensor platform. These results are due to their excellent electrical conductivity, high surface area for utility, and physicochemical stability. The existing challenge for electrochemical-driven sensors is understanding the molecular …

Nanoclays And Curcumin Based Food Packaging Material For Intelligent Food Packaging Applications, Kalpani Y. Perera, Swarna Jaiswal, Amit K. Jaiswal, Shubham Sharma

Articles

Bionanocomposite packaging eco-friendly alternatives with enhanced characteristics. This study aimed to develop a bionanocomposite intelligent packaging. Sodium alginate, gelatin, Curcumin (Cur), glycerol, and Nanoclay (NC) films were prepared. The influences of nanoclay and curcumin on the surface, optical, mechanical, chemical, barrier, and pH-indicating properties were studied. The results showed that the lightness of films was reduced by 1.28 folds compared to NC (control) film, while the yellowness of films increased by 5.82 folds. Film transparency was reduced by 9.3 folds and a 3.46 folds increase in UV barrier properties was observed compared to NC (control) film. The highest tensile strength …

Cold Plasma Technology In Food Packaging, Kalpani Y. Perera, Jack Prendeville, Amit K. Jaiswal, Swarna Jaiswal

Articles

Cold plasma (CP) is an effective strategy to alter the limitations of biopolymer materials for food packaging applications. Biopolymers such as polysaccharides and proteins are known to be sustainable materials with excellent film-forming properties. Bio-based films can be used as an alternative to traditional plastic packaging. There are limitations to biopolymer packaging materials such as hydrophobicity, poor barrier, and thermos-mechanical properties. For this reason, biopolymers must be modified to create a packaging material with the desired applicability. CP is an effective method to enhance the functionality and interfacial features of biopolymers. It etches the film surface allowing for better adhesion …

Exploring The Effect Of Environmental Degradation On The Shape Memory Properties Of Polymers, Jorge Mario Avila

Open Access Theses & Dissertations

A key detriment of the use of polymers by our society is the negative effect this material class has had on the environment. A category of polymers known as shape memory polymers (SMP)s have the ability to return to a programmed original shape form after deformation to a temporary shape by using stimuli such as temperature, electrical pulses and even magnetism. The shape memory effect allows for some polymers to heal if they are damaged. This ability to heal means that components made from these materials can be reused rather than thrown away if they are damaged. The work presented …

Enhancing The Performance Of Poly(3-Hexylthiophene) Based Organic Thin-Film Transistors Using An Interface Engineering Method, Eyob Negussie Tarekegn

All Dissertations

An original design and photolithographic fabrication process for poly(3-hexylthiophene-2, 5-diyl) (P3HT) based organic thin-film transistors (OTFTs) is presented. The structure of the transistors was based on the bottom gate bottom contact OTFT. The fabrication process was efficient, cost-effective, and relatively straightforward to implement. Current–voltage (I-V) measurements were performed to characterize the primary electronic properties of the transistors. The measured mobility of these transistors was significantly higher than most results reported in the literature for other similar bottom gate bottom contact P3HT OTFTs. The higher mobility is explained primarily by the effectiveness of the fabrication process in keeping the interfacial layers …

Design, Fabrication, And Characterization Of Conjugated Polymeric Electrochemical Memristors As Neuromorphic/Integrated Circuits, Benjamin Grant

All Dissertations

Organic materials are promising candidates for future electronic devices compared to the complementing inorganic materials due to their ease of processability, use, and disposal, low cost of fabrication, energy efficiency, and flexible nature toward implementation as flexible and non-conformal devices.With that in mind, electrochemical materials have been widely demonstrated with commercial use as sensors, displays, and a variety of other electronic devices. As Moore's law predicts the increase in the density of transistors on a chip, the requirement to create either smaller transistors or the replacement of the transistor device entirely is apparent. Memory resistors, coined ``memristor", are variable resistive …

Hierarchical Structure And Material Integration For Electrocatalytic Co2 Reduction, Hamed Mehrabi

Graduate Theses and Dissertations

CO2 released by the combustion of fossil fuels is driving significant changes to the earth’sclimate. The natural cycle for removing CO2 from the atmosphere, namely photosynthesis, cannot keep up with the rate at which it is being added. Developing engineering approaches to remove CO2 from the atmosphere is becoming essential to reduce these effects. Removal leads to further issues of carbon sequestration and favorable CO2 reuse strategies, including the electrochemical transformation of recovered CO2 to useful products such as fuels and materials. Copper is an important electrocatalyst for the CO2 reduction reaction (CO2RR) because of its unique capability for producing …

Optimized 3d-Printing Of Carbon Fiber-Reinforced Polyether-Ether-Ketone (Cfr-Peek) For Use In Overmolded Lattice Composite, Ryan C. Ogle

Masters Theses

Current orthopedic implants are overwhelmingly composed from metallic materials. These implants show superior mechanical properties, but this can additionally result in stress shielding due to a modulus mismatch between the bone tissue and implanted device. Polymeric implants reduce this stress shielding effect but have much lower mechanical properties, limiting their use. Polylactic acid (PLA) is a widely used biodegradable thermoplastic polymer, however, its use has been limited by the polymer’s mechanical properties and rapid loss of strength during degradation in vivo. Polyether-ether-ketone (PEEK) is another common biocompatible polymer , with chemical and mechanical properties which make it a popular alternative …

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 …

Biodegradable Active Bio-Nanocomposite Film For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

The increased environmental pollution has led to finding sustainable solutions for non-renewable plastic-based food packaging materials. Thus, the use of biomaterial-based packaging material has become an immense trend. This work aims at developing an antimicrobial biodegradable chitosanalginate bio-nano composite film with TiO2 nanoparticle (NPs) for food packaging applications. The film was developed by a solution casting method. The chemical, mechanical, thermal, barrier, antimicrobial, and biodegradable properties of the packaging films were evaluated. Packaging studies were performed for 15 days for cherry tomatoes. The designed packaging material had enhanced the mechanical properties with a significantly (p < 0.05) higher tensile strength of 15.76 folds and 2 fold higher elongation at break. The UV barrier properties increased by 88.6%, while the film transparency decreased by 87.23%. Molecular interaction of N-H covalent bonds was observed between alginate and chitosan together with TiO2 NPs. The developed bio-nano composite film showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene with a log reduction of 7.08, 7.28, 6.04 & 6.02 log CFU/ml respectively at 24 hours incubation period. The film was completely biodegraded and a weight loss of 89.06% was observed in bio-nanocomposite film during the 3 months. Shelf-life estimation of cherry tomato using developed packaging films showed an increase in the shelf-life up to 8 days with stable pH, total soluble solids, and weight with no bacterial growth when packaged with prepared film. Owing to their improved mechanical, UV barrier, antibacterial, and biodegradability, the prepared active bio-nano composite packaging films could be considered a potential candidate for fruit packaging.

Sodium Alginate, Nanoclay And Curcumin Based Food Packaging Material For Intelligent Food Packaging Applications, Kalpani Y. Perera, Máille Hopkins, Shubham Sharma, Brendan Duffy, Amit K. Jaiswal, Swarna Jaiswal

Articles

Bionanocomposite food packaging contains materials of biological origin which display high-performance activity when compared to biopolymers and are eco-friendly alternatives to conventional packaging materials. Intelligent packaging monitors the condition of the food or environment surrounding the food and communicates changes to the consumer. This study aimed to develop a bionanocomposite intelligent packaging material by utilising sodium alginate, nanoclay and curcumin. Sodium alginate (2 W/V% SA) film incorporated with 0.3 W/V% curcumin (Cur), glycerol, and nanoclay (NC) in various concentrations (0, 0.5, 1 and 2 W/V %) was prepared using the solvent casting method. The influences of nanoclay and curcumin on …

A Machine Learning Approach To Robotic Additive Manufacturing Of Uv-Curable Polymers Using Direct Ink Writing, Luis A. Velazquez

LSU Master's Theses

This thesis presents the design and implementation of a robotic additive manufacturing system that uses ultraviolet (UV)-curable thermoset polymers. Its design considers future applications involving free-standing 3D printing by means of partial UV curing and the fabrication of samples that are reinforced with fillers or fibers to manufacture complex-shape objects.

The proposed setup integrates a custom-built extruder with a UR5e collaborative manipulator. The capabilities of the system were demonstrated using Anycubic resin formulations containing fumed silica (FS) at varying weight fractions from 2.8 to 8 wt%. To fully cure the specimens after fabrication, a UV chamber was used. Then, measurements …

Fabrication Of Thin-Film Composite, Reverse-Osmosis Membranes With Polyethylenimine Modifications For Enhancing Membrane Fouling Resistance, Stephanie N. Hamilton

Master's Theses

Increasing water reuse opportunities for communities has become increasingly important as access to clean water is becoming more scarce. Reverse Osmosis (RO) is an advanced treatment technology used in water recycling wastewater for potable reuse applications. RO is a promising technology; however, the membranes have limitations including their high energy demand and their susceptibility to membrane fouling. The main objective of this study was to develop a reproducible method for the fabrication of RO membranes with enhanced flux and reduced susceptibility to fouling. Literature contains numerous publications on fabrication of thin film composite (TFC) RO membranes with high performance. However, …

Synthesis And Assembly Of Polymer Materials At Interfaces, Xiaoshuang Wei

Doctoral Dissertations

The overarching goal of the thesis is to understand growth and assembly of polymer materials at interfaces. Chapter 2 and Chapter 3 study simultaneous polymer growth and assembly at fluid interfaces, where in-situ photopolymerization and vapor phase deposition were utilized to grow polymers, respectively. Chapter 4 leverages capillary condensation to pattern polymer growth at solid substrates. Chapter 1 provides background information on polymer materials at interfaces, and vapor phase deposition method (initiated chemical vapor deposition, iCVD) to grow polymers. This chapter also reviews polymer thin film wetting, and colloidal assemblies at interfaces. In Chapter 2, we demonstrate the preparation …

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …

Quantifying Elasto-Adhesion And Fluid-Elastic Dynamics For Ultra-Soft Hydrogel Interfaces, Hongbo Fu

Doctoral Dissertations

Hydrogels are constructed with polymer networks swollen with water, which are soft and with much smaller shear moduli than bulk moduli. Due to the similar moduli to biological tissues, synthetic hydrogels have been used for biological applications. While interfacial properties are important for many of the applications of soft materials, quantifying these properties is challenging for ultra-soft materials. Ultra-softness causes difficulties in measuring interfacial properties with conventional force-based methods. For example, soft specimens deform largely under gravity and external forces, and thus the assumptions of the established methods are invalid. Additionally, many of the applications for hydrogels require them to …

Bio-Based Food Packaging Material For Intelligent Food Packaging Applications For Chicken Fillets, Kalpani Y. Perera, Amit K. Jaiswal, Swarma Jaiswal, Shubham Sharma

Articles

Bionanocomposite packaging is made up of bio- based materials that have high performance activity and are ecologically sustainable alternatives to packaging made of synthetic polymers. Intelligent packaging retains track of the state of the food and the environment in which it is stored, and communicates relevant changes to the consumer through visualization or other methods. The aim of this study was to develop a bionanocomposite intelligent packaging material by utilising sodium alginate, gelatin, nanoclay and curcumin. Sodium alginate, gelatin film incorporated with Curcumin (Cur), and Nanoclay (NC) in various concentrations (0% W/V, 0.5% W/V, 1% W/V and 1. 5% W/V) …

Enabling Nanoimprint Lithography Techniques Across Multiple Manufacturing Processes, Vincent Einck

Doctoral Dissertations

Advanced nanooptics in the areas of flat lenses, diffractive elements, and tunable emissivity require a route to high throughput manufacturing. Nanooptics are often demanding of high refractive index materials, nanometer precision and ease of fabrication. Nanoimprint lithography (NIL) is a low-cost, high throughput manufacturing technique beginning to be realized in commercial industry.^1,2 The NIL process is an ideal manufacturing candidate due to its ability to have a fast process time, efficient use of materials, repeatability and high precision while also having wide diversity of potential structures and material choices. Appling NIL techniques to other facets of manufacturing enable the …

Biobased Packaging Materials From Cellulose Nanofibrils Produced From Virgin Wood Pulp Or Recycled Cardboard Pulp, Md Ikramul Hasan

Electronic Theses and Dissertations

Self-standing cellulose nanofibril (CNF) films are regarded as one of the promising alternatives to current petroleum-based packaging materials. The mechanical and barrier properties of CNF films are not yet up to the mark for certain applications, especially at high relative humidity. Those properties of CNF films can be tuned by the drying methods of films, degree of fibrillation, cross-linking, and controlled shrinkage. A comprehensive understanding of these processes and their influence on the structure and properties of CNF films have been presented in this thesis.

First, we prepared CNF films from CNF suspensions with two different degrees of fibrillation- standard …

Contact Dewatering Of Cellulose Nanofibers For Biopolymer Composite Applications, Alexander Collins

Electronic Theses and Dissertations

Cellulose Nanofibrils (CNFs) are promising materials for reinforcement of polymer matrices attributable to their impressive physical and mechanical properties, as well as their biodegradability. However, the utilization of these materials in composites is made challenging by the water content of CNF slurries, the tendency of CNFs to agglomerate as they dry, and incompatibility between hydrophilic CNFs and hydrophobic polymer matrices. The most commercially viable drying methods to produce small-scale dry CNFs, such as spray drying, are very energy intensive, can only dry the materials down to micron-scale agglomerates, and do not preserve fibrillar aspect ratios. “Contact dewatering,” or the removal …

Investigating Features And Output Correlation Coefficient Of Natural Fiber-Reinforced Poly(Lactic Acid) Biocomposites, Andreas Federico, Siti Norasmah Surip, Wan Nor Raihan Wan Jaafar, Jaka Fajar Fatriansyah, Agrin Febrian Pradana

Journal of Materials Exploration and Findings (JMEF)

Polylactic acid (PLA) material has the potential to be applied in various industrial fields, but this material has shortcomings in terms of mechanical properties, especially mechanical strength, due to brittleness nature of PLA. The manufacture of PLA composite material with the addition of natural fibers as a reinforcing phase is one of the methods to increase the impact strength and maintain the biodegradable properties of the material. However, in theory, there are many factors that affect the mechanical properties of composite materials, thus making the mechanical properties of composites more complex than monolithic materials. The mechanical properties of these composite …

Numerical Modeling Of Localized Heating In Continuous Fiber Reinforced Thermoplastic Laminates, James T. Gayton

Electronic Theses and Dissertations

The manufacturing of continuous fiber-reinforced thermoplastic (CFRTP) laminates requires the application of heat and pressure. Standard CFRTP manufacturing methods like thermoforming take a global approach to manufacturing, where the whole part is heated and undergoes a forming process. There is an opportunity to develop advanced manufacturing methods based on localized heating and deformations of consolidated stock. This thesis provides a localized heating method via networks of resistive heating elements embedded within the laminate and a means to evaluate that method.

Typical heating methods for CFRTP laminates include infrared and convective ovens or surface contact heaters. They have the same drawbacks …

Functional Bottlebrush Polymer Additives For Thin Films And Coatings, Travis S. Laws

Doctoral Dissertations

Bottlebrush polymers are a class of highly branched polymers consisting of polymeric side chains that are densely grafted to a linear backbone. Their highly branched architecture results in surface enrichment across a broad range of materials. The goal of my research has been centered around the design of functional bottlebrush polymers and their use as surface active additives in blend films and coatings.

In the first chapter, we examine the segregation behavior of polystyrene bottlebrushes that are blended with linear polystyrene. We systematically vary the lengths of the bottlebrush backbone (Nb), side-chain (Nsc), and the linear matrix (Nm) in order …

How Dynamic Bond Results In The Unique Viscoelastic Behavior Of The Associating Polymers, Sirui Ge

Doctoral Dissertations

Associating polymer is a special kind of polymer possessing transient reversible bonds in addition to the conventional covalent bonds. The reversible bonds provide unique dynamics and fascinating viscoelastic properties, resulting in attractive applications for these polymers, such as self-healing and shape memory materials. Despite many years of studies, the understanding of dynamics of polymers with reversible bonds, especially on molecular level, is still in the rudimentary stage, preventing the rational design of the potential novel functional materials based on associating polymers. In this dissertation, we provide a detailed and quantitative understanding of the dynamics and viscoelastic properties of associating polymers. …

Modeling Phase Behavior And Agglomeration In Polymer Systems Incorporating Complex Architectures: From Bottlebrush To Lysozyme, Sidong Tu

All Dissertations

Using computational modeling, we focus on the phase behavior of multicomponent systems incorporating enzyme and bottlebrush polymers where the agglomeration of multiple components occurs. We start with all-atom molecular dynamics (MD) simulations of lysozyme and polyethylene glycol (PEG) based polymer mixture to understand the mechanisms of preservation of lysozyme bioactivity at high temperatures with addition of PEG-derived bottlebrushes. We show that the PEG part of bottlebrushes phase separates at high temperature and shells the access of water to lysozyme, resulting in the preservation of lysozyme secondary structures. We then developed a coarse-grained model using a Dissipative Particle Dynamics approach to …

Brain Inspired Organic Electronic Devices And Systems For Adaptive Signal Processing, Memory, And Learning., Subhadeep Koner

Doctoral Dissertations

A new class of electronic device has emerged which bear the potential for low powered brain like adaptive signal processing, memory, and learning. It is a non-linear resistor with memory coined as memristor. A memristor is a two-terminal electrical device which simultaneously changes its resistance (processing information) and store the resistance state pertaining to the applied power (memory). Therefore, it can collocate memory and processing much like our brain synapse which can save time and energy for information processing. Leveraging stored memory, it can thereby help future engineered systems to learn autonomously from past experiences. There has been a growing …

Polynorbornenes For Advanced Applications And Processes, Xinyi Wang

Doctoral Dissertations

Polynorbornenes have dramatically different properties and various applications depending on their chemical structures. The modular nature of norbornene-based systems provides a facile route toward synthesizing diverse polymeric materials, thus making them ideal materials for systematic structure-property investigations. Herein, their application as gas separation membranes and the correlation between their gas-transport properties and polymer structures will be investigated. Though many valuable correlations between gas-permeability and polynorbornene structure have been studied previously, many of these efforts have focused heavily on designing materials with various chemical structures to achieve high permeabilities. In contrast, the influence of molecular structure on: a) polynorbornene chain packing …

Characterization Of Thermal Gelation Properties In Bioresorbable Thermally Activated Hydrogel Polymers For Hernia Surgery Applications, Alexander Mayfield

All Theses

Hydrogel adhesives are a new class of materials with excellent biocompatibility, which makes them very attractive for biomaterial applications. It has been previously shown that Tetronic T1107, a four-arm poly (propylene oxide)-poly (ethylene oxide) (PPO-PEO) block copolymer, is useful as a chemical crosslinking thermo-responsive hydrogel for bioadhesive applications. The end groups of this polymer are modified with acrylate and N-hydroxysuccinimide (NHS) functional groups. The acrylate end group gives the polymer cohesive properties with long-range chemical crosslinking using dithiothreitol (DTT), while the NHS end group gives the polymer adhesive properties through bonding with amines found in organic tissue. It was found …