Predicting Long-Term Creep Behavior Using Short-Term Stress Relaxation Data In Expanded Polyethylene Foam,
2025
Clemson University
Predicting Long-Term Creep Behavior Using Short-Term Stress Relaxation Data In Expanded Polyethylene Foam, Andrew M. Seelig
All Theses
Closed cell expanded polyethylene (EPE) foams are widely used for protective packaging due to their high energy absorption properties and recyclability. However, these foams can be subjected to sustained compressive stresses (13.78 - 36.20 kPa), depending on density and application, leading to time-dependent deformation (creep). Creep reduces cushioning performance, making its understanding critical for effective protective packaging. Two standards, ASTM D3575 and ASTM D2221, define methods for conducting compressive creep tests on foam materials, with test durations extending up to 1000 hours. Accelerated methods such as Time Temperature Superposition (TTS) and the Stepped Isostress Method (SSM) have been explored for …
Effect Of Cryo-Milling On Pla/Cmc And Pla/ Caco3 Composites: A Comparison Study,
2025
Thomas Jefferson University
Effect Of Cryo-Milling On Pla/Cmc And Pla/ Caco3 Composites: A Comparison Study, Fatemeh Mahdiyeh-Boroujeni, Ron Kander
School of Design and Engineering Papers
This study examines a new approach for improving the dispersion of hydrophilic fillers into a hydrophobic polymer matrix, a long-standing challenge that often limits the thermal and mechanical performance of biocomposites. Two different fillers, natural cellulose microcrystals (CMC) and mineral calcium carbonate (CaCO3), were incorporated into polylactic acid (PLA) at five different weight fractions. Biocomposite films were prepared using physical mixing and cryo-milling, followed by hot pressing. Cryo-milling was explored as a strategy to enhance filler distribution within the matrix. Thermal properties, crystallization behavior, and mechanical performance were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile testing, …
The Science And Economics Of 3d-Printed Filament Recycling,
2025
Embry-Riddle Aeronautical University
The Science And Economics Of 3d-Printed Filament Recycling, Michael Domingo, Dane Freund, John Mcswiggin, Adam Meadows
Sustainability Conference
In recent years, 3D printing has grown rapidly, both in homes and commercially. This has led to increased demand for plastic filaments, many of which contribute to plastic waste. This project explores the potential of recycling household plastics into 3D printing filament, promoting sustainability and creating a circular economy. Materials like PLA, PETG, ABS, and polypropylene can be recycled or even composted. Existing research has shown that recycled filaments can maintain comparable tensile strength to their virgin counterparts, depending on the recycling process. Furthermore, implementing circular economy practices for plastics could save billions annually by mitigating pollution and reducing landfill …
Characterization Of The Fatigue Threshold Behavior Of Uhmwpe,
2025
University of California - Berkeley
Characterization Of The Fatigue Threshold Behavior Of Uhmwpe, Bethany B. Smith, Anurag Roy, Robert O. Ritchie, Lisa A. Pruitt
Faculty Journal Articles
Ultra-high-molecular-weight-polyethylene (UHMWPE) has been the material of choice for bearings in total joint replacements (TJRs) for decades as a result of its excellent wear resistance, chemical inertness, energetic toughness, low friction, and biocompatibility. Utilization of this polymer in orthopedic devices requires oxidation, wear, and fatigue resistance. Balancing these important properties by tailoring processing techniques and modulating microstructural features has been an ongoing endeavor in the field. Research into the clinical applications of UHMWPE has primarily focused on the challenges of wear and oxidation while studies into the realm of fatigue have been more limited. Literature gaps exist in fully understanding …
Ferric Metal-Organic Frameworks (Mofs)-Based Electrospinning Fibers For Supercapacitors,
2025
The British University in Egypt
Ferric Metal-Organic Frameworks (Mofs)-Based Electrospinning Fibers For Supercapacitors, Samar A. Salim, Hani Nasser Abdelhamid
Nanotechnology Research Centre
Ferric-based metal-organic frameworks (Fe-MOFs) were synthesized and incorporated into poly(methyl methacrylate) (PMMA) using electrospinning to produce PMMA_Fe-MOF nanofibers. The materials were analyzed using X-ray diffraction (XRD), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM). The electrospun materials were directly integrated into nickel foam (NF) electrodes for energy storage applications, e.g., supercapacitors. The electrochemical performance was assessed using cyclic voltammetry (CV), galvanostatic charge-discharge curves (GCDC), linear sweep voltammetry (LSV), and electrochemical potentiokinetic reactivation (EPR). The PMMA_Fe-MOF electrodes exhibited outstanding capacitive performance, achieving specific capacitances of up to 1017.5 F/g at 1 A/g for the 2.5 % Fe-MOF …
Understanding Structure-Property Relationships Within Polyolefin-Derived Vitrimer Systems,
2025
University of Southern Mississippi
Understanding Structure-Property Relationships Within Polyolefin-Derived Vitrimer Systems, Mikaela Sadri
Dissertations
Polyolefins are extremely ubiquitous materials due to their satisfactory material properties, ease of synthesis, and low cost. Unfortunately, their extensive use has led to a global plastic waste mismanagement problem. As such, notable efforts have recently focused on converting these commodity polymers into vitrimers, or dynamic networks, to extend their use-life and tailor their properties. However, the fundamental polymer physics of these emerging materials, remain largely underexplored, hindering their widespread implementation. To address this challenge and enable a more sustainable future, the overarching goal of my dissertation research is to understand the fundamental structure-property relationships within complex polyolefin-derived vitrimer systems. …
Controlling Electroless Deposition On Polymer Interfaces Towards Discrete Functional Particle Synthesis,
2025
University of Arkansas-Fayetteville
Controlling Electroless Deposition On Polymer Interfaces Towards Discrete Functional Particle Synthesis, Grecia Pierina Alvarado Munoz
Graduate Theses and Dissertations
Electroless deposition is a process that facilitates the formation of metal layers on surfaces through the reduction of metal ions onto a surface in the presence of a sacrificial reducing agent. This process can be applied to synthesize conductive metal layers on insulators such as glass or polymers. The kinetics of heterogeneous deposition depend on the interfacial surface chemistry, including the presence of added catalyst materials, as well as the bulk chemical environment, such as the concentration of metal ions and sacrificial reductants. Furthermore, the homogeneous formation of metal nanoparticles may compete with the deposition reaction, adversely affecting the control …
Designing Self-Healable Aromatic Copolymers And Olefinic Composites,
2025
Clemson University
Designing Self-Healable Aromatic Copolymers And Olefinic Composites, Samruddhi Yashwant Gaikwad
All Dissertations
Self-healing polymers capable of recovering from mechanical damage are promising materials for advanced applications, especially those involving mechanical and/or physical fatigue. In these studies, we have developed techniques to achieve autonomous self-healing in commodity Styrene/n-butyl acrylate copolymers. The mechanism of self-healing in the designed polymers involves inter-and/or intrachain non-covalent interactions between π-cloud and polar linkages of acrylic nBA in random/preferentially alternating copolymers. A combination of spectroscopic tools, thermo-mechanical analysis, and molecular dynamics (MD) simulations has been used to elucidate the mechanism of self-healing. These studies further show the incorporation of dipolar C-F groups to understand the effect of having fluorinated …
Self-Poled P(Vdf-Trfe) Based Composites For Energy Harvesting And Wearable Sensor Applications,
2025
Clemson University
Self-Poled P(Vdf-Trfe) Based Composites For Energy Harvesting And Wearable Sensor Applications, Lavanya Muthusamy
All Dissertations
The growing demand for flexible, low-power, and self-powered wearable electronic systems has accelerated research interest in polymer-based sensors and energy harvesting technologies. Among piezoelectric polymer materials, Poly(vinylidene fluoride-trifluoro ethylene) [P(VDF-TrFE)], over the years, has garnered significant attention due to its unique piezoelectric properties, high dielectric constant, mechanical flexibility, thermal stability, chemical resistance, biocompatibility and compatibility with scalable fabrication processes. Despite its advantages, conventional P(VDF-TrFE)-based devices often require external poling and face limitations in integration with low-cost, flexible substrates. To overcome these limitations, this research study explores the nanofiller approach, along with facile fabrication processes, and structural design strategies aimed at …
Polymer-Enhanced Nanopore Sensing,
2025
University of Arkansas-Fayetteville
Polymer-Enhanced Nanopore Sensing, Eugene Gyasi Agyemang
Graduate Theses and Dissertations
The resistive pulse technique characterizes single analytes by detecting fluctuations in the ion current as they pass through a narrow orifice connecting two electrolyte-filled chambers, each containing a single electrode. The amplitude, shape, frequency, and duration of these fluctuations primarily provide information about the analyte’s size, shape, concentration, and net surface charge, respectively. One configuration for resistive pulse measurements is of an electrolyte-filled nanopipette immersed in a bath, where the nanopipette tip acts as the nanoscale orifice. It was previously shown that incorporating the large quantities polymer polyethylene glycol (PEG 8K, 50% w/v) into the external electrolyte bath dramatically enhanced …
Preparation And Characterization Of Electrospun Pvdf-Based Nanocomposite Fibers For Energy Harvesting And Storage Applications,
2025
Thin Films Laboratory, Physics Department, Faculty of Science, Suez Canal University, 41522, Ismailia, Egypt
Preparation And Characterization Of Electrospun Pvdf-Based Nanocomposite Fibers For Energy Harvesting And Storage Applications, Ahmed Ramzy, Electrochemistry And Corrosion Laboratory, Physical Chemistry Department, National Research Centre, Dokki, Cairo, 12622, Egypt, Ahmed M. El-Mahalawy
Nanotechnology Research Centre
This study introduces the development of multifunctional electrospun polyvinylidene fluoride (PVDF) composite films doped with potassium octatitanate (KTO) for advanced energy applications. The research tackles key challenges in energy generation and storage through innovative material design and detailed characterization. Adding 0.2 wt% KTO to PVDF electrospun fibers resulted in a notable increase in crystallinity to 78.51 %, marking a significant enhancement in material properties. Structural analysis using X-ray diffraction and Fourier transform infrared spectroscopy confirmed optimal phase composition, while morphological features were verified through field emission scanning electron microscopy. The composite films showed exceptional electrochemical performance, with bulk electrolyte resistance …
Effect Of Sorbitol Plasticizer On Bioplastics Properties Based On Oil Palm Empty Fruit Bunches (Opefb) And Jackfruit Seed Starch,
2025
Department of Materials and Metallurgical Engineering, Institut Teknologi Kalimantan, Balikpapan 76127, Indonesia
Effect Of Sorbitol Plasticizer On Bioplastics Properties Based On Oil Palm Empty Fruit Bunches (Opefb) And Jackfruit Seed Starch, Nia Sasria, Vita Nur Afifah, Gusti Umindya Nur Tajalla
Makara Journal of Science
In bioplastics, natural materials that are easily decomposed are used to minimize plastic waste. In this research, the compositions used were cellulose from oil palm empty fruit bunches (OPEFB), jackfruit seed starch, and carboxymethyl cellulose (CMC) as a filler with sorbitol as a plasticizer. This study aimed to analyze the effect of a sorbitol plasticizer on bioplastic properties. The study began by extracting jackfruit seed starch and OPEFB cellulose. Subsequently, bioplastics were prepared by varying sorbitol, namely 0 (S – 0), 0.5 mL (S – 0.5), 1 mL (S – 1), and 1.5 ml (S – 1.5), with CMC 20%. …
Synthesis And Radical Polymerization Of N,N-Diallyl Phthalimide,
2025
Tashkent Institute of Chemical Technology, Tashkent, Uzbekistan
Synthesis And Radical Polymerization Of N,N-Diallyl Phthalimide, Oytura S. Maksumova, Feruza A. Pulatova, Dilnozakhon I. Tursunova, Feruza A. Makhmudova
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of this work is the synthesis of iodine N,N-diallylphthalimide and the study of its radical polymerization. In this regard, the synthesis of iodine N,N-diallylphthalimide was carried out in two stages: at the first stage, phthalic anhydride reacts with allylamine and forms allyl phthalimide, at the second stage, allyl phthalimide reacts with allyl iodide to form iodine N, N-diallyl phthalimide. Radical polymerization of the synthesized quaternary salt of N, N-diallyl phthalimide was studied in the presence of the initiator dinitrile azobisisobutyric acid at relatively low temperatures. Kinetic features of the polymerization reaction of iodine N, N-diallyl phthalimide were considered. …
Poly(Pyridinium Salt)S Containing 9,9-Bis(4- Aminophenyl)Fluorene Moieties With Various Organic Counterions Exhibiting Both Lyotropic Liquid-Crystalline And Light-Emitting Properties,
2025
University of Nevada, Las Vegas
Poly(Pyridinium Salt)S Containing 9,9-Bis(4- Aminophenyl)Fluorene Moieties With Various Organic Counterions Exhibiting Both Lyotropic Liquid-Crystalline And Light-Emitting Properties, Pradip K. Bhowmik, David King, Haesook Han, Andras F. Wacha, Matti Knaapila
Chemistry and Biochemistry Faculty Research
Main-chain conjugated and non-conjugated polyelectrolytes are an important class of materials that have many technological applications ranging from fire-retardant materials to carbon-nanotube composites, nonlinear optical materials, electrochromic materials for smart windows, and optical sensors for biomolecules. Here, we describe a series of poly(pyridinium salt)s-fluorene containing 9,9-bis(4-aminophenyl)fluorene moieties with various organic counterions that were synthesized using ring-transmutation polymerization and metathesis reactions, which are non-conjugated polyelectrolytes. Their chemical structures were characterized by Fourier transform infrared (FTIR), proton (1H) and fluorine 19 (19F) nuclear magnetic resonance (NMR) spectrometers, and elemental analysis. They exhibited polyelectrolytic behavior in dimethyl sulfoxide. Their lyotropic liquid-crystalline phases were …
Effects Of Aloe Vera/Chitosan Ratios On The Tensile Properties Of Aloe Vera/Chitosan/Polyvinyl Alcohol Nanofibrous Membranes For Wound Care Dressing,
2025
Department of Mechanical Engineering, Faculty of Engineering, Universitas Muhammadiyah Yogyakarta, Yogyakarta 55183, Indonesia
Effects Of Aloe Vera/Chitosan Ratios On The Tensile Properties Of Aloe Vera/Chitosan/Polyvinyl Alcohol Nanofibrous Membranes For Wound Care Dressing, Harini Sosiati, Abdul Rahman, Kelvin Kurniawan Sahputra, Miftahul Faruq Ibnul Fatoni
Makara Journal of Science
Chitosan (CS) and Aloe vera (AV) are functional and antibacterial materials compatible with polyvinyl alcohol (PVA), which confers medical and healthcare potential. This study prepared and then characterized the influence of CS/AV ratios on the tensile properties of CS/AV/PVA nanofibrous membranes for wound care dressing materials. The CS/AV/PVA membranes were fabricated using an electrospinning technique at varying AV/CS/PVA volume ratios: 0:0:100, 0:20:80, 5:15:80, 10:10:80, 15:5:80, and 20:0:80. All membranes were subjected to tensile testing as per the ASTM 882 standard, and the nanofiber’s morphology was examined using scanning electron microscopy. Changes in the tensile strength related to the formation of …
Degradation Characterization Of Nopal-Based Biopolymer Made From Opuntia Sp. Juice, Beeswax, Animal Protein, And Polyvinyl Alcohol,
2025
California Polytechnic State University, San Luis Obispo
Degradation Characterization Of Nopal-Based Biopolymer Made From Opuntia Sp. Juice, Beeswax, Animal Protein, And Polyvinyl Alcohol, Logan Williams, Mary Elizabeth Holland, Spencer Williams
Materials Engineering
Since the introduction of polymers in the 1960s, there has been an exponential increase in use. Driven by rapidly growing demand, the volume of polymers in the production, application, and end-of-life stages has surged. The widespread use of these materials has led to escalating environmental pollution, which disrupts ecosystems, and contributes to global ecological degradation. While advancements in recycling technologies and infrastructure have shown promise, they have not maintained pace with polymer production and disposal. This imbalance warrants research into sustainable alternatives. Environmentally benign polymers derived from renewable sources and exhibiting minimal ecological impact at the end of their life …
Chemical Recycling Of Pet Plastic Waste,
2025
California Polytechnic State University, San Luis Obispo
Chemical Recycling Of Pet Plastic Waste, Charlie Parker, Benjamin Puga, Jake Verschoor
Materials Engineering
The growing accumulation of plastic waste, specifically polyethylene terephthalate (PET), has driven the need for more efficient and scalable chemical recycling methods. This study investigated the methanolysis of PET using zinc oxide (ZnO) nanoparticles as a catalyst and tetrabutylammonium chloride (NBu₄Cl) as an ionic liquid, aiming to reduce methanol consumption while achieving high PET conversion efficiency. ZnO nanoparticles were synthesized via wet chemistry and characterized using Dynamic Light Scattering (DLS), which showed an average particle size of 13.5 nm with a polydispersity index of 0.1556, indicating a moderately-high monodisperse distribution of particles sufficient for reactions. The main conversion product, dimethyl …
Low Earth Orbit Drag Sail Degradation Due To Atomic Oxygen And Ultraviolet Radiation,
2025
California Polytechnic State University, San Luis Obispo
Low Earth Orbit Drag Sail Degradation Due To Atomic Oxygen And Ultraviolet Radiation, Hannah Rost
Master's Theses
As the orbital debris population increases, so does the risk of collisions with operational spacecraft. In response, the Federal Communications Commission has shortened the deorbit requirement from 25 years to five years. While natural atmospheric decay was sufficient under the previous guideline, many objects with low area to mass ratios can no longer passively comply. Smaller, non-propellant-carrying space objects such as CubeSats lack the ability to maneuver and must rely on alternative deorbit methods. One proposed solution is to deploy a drag sail at end of life to increase atmospheric drag and accelerate orbital decay. However, exposure to atomic oxygen …
Multimodal Self-Folding Of Shape Memory Polymer Using Laser Induced Graphene,
2025
Cal Poly
Multimodal Self-Folding Of Shape Memory Polymer Using Laser Induced Graphene, Liam Harrison Drew
Master's Theses
Shape memory polymers (SMPs) can undergo programmed shape transformations when heated above their glass transition temperature (Tg), enabling actuation through stimuli such as infrared (IR) radiation and Joule heating. These materials are promising for deployable systems and soft robotics due to their lightweight structure and elimination of traditional mechanical components. While IR-based actuation is simple and low-cost, it lacks precision in uncontrolled environments. Joule heating offers improved control but is often limited by conductive ink properties such as thickness, stiffness, or poor adhesion. This work introduces a novel method for multimodal SMP actuation using laser-induced graphene (LIG) transferred …
Investigation Into Silicone-Silicate Conversion Due To Atomic Oxygen In The Low Earth Orbit Environment,
2025
California Polytechnic State University, San Luis Obispo
Investigation Into Silicone-Silicate Conversion Due To Atomic Oxygen In The Low Earth Orbit Environment, Justin T. Self
Master's Theses
Silicones have been widely used over the years in spacecraft for a variety of functions, but atomic oxygen (AO) exposure in Low Earth Orbit causes a silicate (SiO2) surface layer to rapidly develop on the silicone which results in a permanent change in its thermal and optical properties. Although this silicone to silicate conversion is known to occur, statistical predictions of layer formation as a function of time on orbit are not found in literature. This thesis utilized optical and scanning electron microscopy, Fourier-Transform Infrared Spectroscopy, diffuse reflectance spectroscopy, and nonlinear regression statistical techniques after RF plasma asher …
