Polymer Science Commons^™

Experimental Evaluation Of Membranes In The Recovery Of Hydrogen From Serpentinization, Rafael Dos Santos

LSU Master's Theses

Natural hydrogen generated through serpentinization reactions has emerged as a promising low-carbon energy resource. However, serpentinization-derived gas streams commonly contain methane (CH₄) and carbon dioxide (CO₂), requiring purification before hydrogen can be utilized in industrial applications. Membrane-based gas separation technologies offer a potentially cost-effective solution for hydrogen recovery; however, to the best of the author's knowledge, no previous studies have specifically investigated their application to serpentinization-derived gas streams.

This work evaluates the performance of two commercial polymeric membrane modules (Evonik and Generon) and one palladium-copper (Pd-Cu) membrane module (Okaya) for hydrogen recovery from gas compositions representative of serpentinization environments. An …

Mechanistic Insights Into Polymer-Assisted Graphene Exfoliation: The Roles Of Velocity, Adhesion, Cohesion, Temperature, Peeling Mode, And Edge Defect Via Coarse-Grained Molecular Dynamics, Linjiale Dai

All Theses

Graphene exfoliation is a critical step in the fabrication of high-quality graphene

layers. However, the underlying fracture mechanisms remain poorly understood. In this

work, I employed coarse-grained (CG) molecular dynamics (MD) simulations to

investigate how factors such as interfacial binding energy, substrate cohesion, temperature,

peeling mode, and edge defects influence the outcome of the exfoliation process. To model

polymer-assisted mechanical exfoliation, I used a finite-size system in which multilayer

graphene (MLG) is sandwiched between two thin polymer films. Leveraging the

spatiotemporal efficiency of the CG model, I performed fifty simulation iterations per

parameter set and analyzed the results from a …

Biobased Acrylate Composites With Enhanced Strength For Additive Manufacturing, Nicole Wagner, Joseph Mcwherter

Engineering Faculty Articles and Research

With the expanding use of polymers in additive manufacturing, sustainable resins for use in vat photopolymerization are required to reduce their environmental impact. One promising approach to achieve this is to incorporate biobased fillers that replace the acrylates in photopolymer resins as ‘green’ alternatives. In this study, photopolymer composites consisting of a methacrylate resin with varying calcium carbonate powder content between 0 and 50 wt.% were investigated. A digital light processing technique was used to fabricate tensile test specimens for mechanical testing. Good printability, dimensional accuracy, and good interlayer adhesion were observed for composite resin formulations that incorporated calcium carbonate …

Polymorphism And Mechanical Behavior In Hot-Pressed 3d-Printed Polyamide Composite: Effects Of Pressure And Temperature, John Barber, Patricia Revolinsky, Jimesh Bhagatji, Diego Pedrazzoli, Sergii Kravchenko, Oleksandr Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

The aim of this work is to study the effect of high-temperature compaction (HTC) upon the polymorphism and the mechanical behavior of an additively manufactured (AM) carbon fiber-reinforced polyamide (PA6). Different pressure and temperature levels during HTC were tested to determine the overall effect on the mechanical behavior and material crystalline composition. Treated, carbon fiber-reinforced PA6 samples were analyzed using differential scanning calorimetry, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and three-point bending testing. When considered with respect to as-printed samples, an HTC temperature of 190 °C combined with 80 psi pressure resulted in an increased flexural modulus and strength …

A Comprehensive Review Of Piezoelectric Pvdf Polymer Fabrications And Characteristics, Nadia Ahbab, Sidra Naz, Tian-Bing Xu, Shihai Zhang

Mechanical & Aerospace Engineering Faculty Publications

Polyvinylidene fluoride (PVDF) polymer films, renowned for their exceptional piezoelectric, pyroelectric, and ferroelectric properties, offer a versatile platform for the development of cutting-edge micro-scale functional devices, enabling innovative applications ranging from energy harvesting and sensing to medical diagnostics and actuation. This paper presents an in-depth review of the material properties, fabrication methodologies, and characterization of PVDF films. Initially, a comprehensive description of the physical, mechanical, chemical, thermal, electrical, and electromechanical properties is provided. The unique combination of piezoelectric, pyroelectric, and ferroelectric properties, coupled with its excellent chemical resistance and mechanical strength, makes PVDF a highly valuable material for a wide …

Optimization Of Tps Films Using An Adaptive Design Of Experiments Approach In A Bayesian Optimization Framework, Theresa Marks, Gracie White, Scott Lohman, Mayank Malhotra

The Journal of Purdue Undergraduate Research

Plastic pollution, amounting to 12 million tons annually, necessitates sustainable alternatives to single-use plastics. Compostable thermoplastic starch (TPS) films show promise but lack strength and durability compared to traditional plastics. This study employs an adaptive design of experiments (DoE) approach to enhance TPS films by optimizing testing points. The research focuses on varying concentrations of plasticizers (acetic acid and glycerol) in a water and potato starch mixture, aiming to identify the optimal ratio maximizing tensile strength and % elongation at break. Gaussian process regression (GPR) with uncertainty estimation and Bayesian optimization (BO) utilizing an acquisition function (AF) are employed. The …

Fundamental Study Of Nonlinear Electrophoresis, Joseph Armakan Bentor

All Dissertations

Classical electrophoretic theory describes the linear response of particles suspended in Newtonian fluids under weak electric fields. When the electric field exceeds this weak limit, a nonlinear response arises due to non-uniform surface conduction over the curved particles. This nonlinear behavior introduces dependencies on fluid and particle properties not considered in the classical theory, offering potential advantages for microfluidic particle manipulation. While this phenomenon has been extensively studied theoretically and numerically in Newtonian fluids, experimental investigations have been relatively limited.

Fluid rheology can significantly alter particle dynamics under applied electric fields. Rheological properties like shear-thinning and elasticity which are not …

Research On 3d Printing Resin Exposure Properties And Its Application On Centrifugal Microfluidic Platform Based On Fluorescence Detection, Zheng Qiao

LSU Doctoral Dissertations

This dissertation encapsulates significant advancements in the field of SLA 3D printing and centrifugal microfluidics. Central to the research is the development of a novel mathematical model for predicting trapped resin thickness in SLA 3D printing, a groundbreaking contribution that addresses a critical aspect of printing intricate structures. This model, the first to establish a mathematical relationship for resin thickness, is rooted in a comprehensive study of the resin curing process. The research leverages the concept of 'critical dosage' for resin curing, leading to a more refined and theoretically grounded approach for calculating curing thickness. Experimentation further validates the model, …

Schaeffler Icvd Coating Machine, Louis Mcgrath

Williams Honors College, Honors Research Projects

Chemical Vapor Deposition (CVD) is mutual technology used to deposit thin film through a gaseous phase by vaporizing the solid materials. This conventional process usually requires high thermal stability of the materials, which is not applicable for most of the polymeric materials. Therefore, a novel process, initiated Chemical Vapor Deposition (iCVD) is developed by introducing the gaseous monument and initiator to form the thin film in-situ. By adjusting the free-radical polymerization in the vapor phase, a variety of thin and uniform polymer films can be achieved. Depending on the chemistry, iCVD has many categories. This report explains the design …

Characterization Of Interlayer Laser Shock Peening During Fused Filament Fabrication Of Polylactic Acid (Pla), Fabien Denise

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

The field of additive manufacturing (AM) has gained a significant amount of popularity due to the increasing need for more sustainable manufacturing techniques and the adaptive development of complex product geometries. The problem is that AM parts routinely exhibit flaws or weaknesses that affect functionality or performance. Over the years, surface treatments have been developed to compensate certain flaws or weaknesses in manufactured products. Combining surface treatments with the modularity of additive manufacturing could lead to more adaptable and creative improvements of product functions in the future. The current work evaluates the feasibility of pursuing a new research axis in …

Cellulose Materials For Drug Delivery Applications, Reham Mohamed

Mechanical Engineering Theses

Non-healing wounds are a growing global public health concern due to inadequate or ineffective therapeutic products available. Cellulose-based biopolymers are attractive wound dressing materials due to their biocompatibility, biodegradability, non-toxicity, and cost-effectiveness. This study aims to design and fabricate solid dosage formulations using carboxymethyl cellulose (CMC) and ethyl cellulose (EC) to facilitate multi-stage releases of phenytoin (PHT) and tetracycline hydrochloride (TCH) from plain carriers, fibers/films composites, and layer-by-layer fiber composites. Results from in vitro drug release assays demonstrated a time-dependent release up to 8 hours from PHT-loaded EC fibers, while TCH-loaded CMC films exhibited a rapid release within 5 minutes. …

Characterization Of Mechanically Recycled Polylactic Acid (Pla) Filament For 3d-Printing By Evaluating Mechanical, Thermal, And Chemical Properties And Process Performance, Mahsa Shabani Samghabady

All Theses

Polylactic acid (PLA) is a biopolymer made from renewable resources such as sugar and corn. PLA filament is a popular material used in Fused Deposition Modeling (FDM) 3D-printing. While this material has many advantages, all the failed parts, support structures, rafts, nozzle tests, and the many prototype iterations during the 3D-printing process contribute to the plastic pollution and release of greenhouse gases. Although PLA is biodegradable, it can take years to degrade in landfills. Instead of throwing away PLA waste and buying new filaments, PLA can be recycled. Amongst the different recycling technologies, mechanical recycling is the most environmentally friendly. …

Hydrothermal Liquefaction Of Saccharina Latissima For The Production Of Biofuel, Mayokun A. Oke

Mechanical Engineering Theses

We performed hydrothermal liquefaction of brown macroalga (Saccharina latissima) in the presence of homogenous and heterogenous catalysts such as KOH, Na₂CO₃, Pd/C, HZSM-5, Ce/HZSM-5, and Ni/SiO₂-Al₂O₃ in hot compressed water, to investigate their effects on product yield and composition in the biocrude. To investigate hydrocarbon production, we used methanol as co-solvent (methanol-to-water 1/4 vol.%) and as the only liquefaction solvent. We carried out the experiments in a batch reactor at 330^oC and 120-130 bar, and varying temperature, algae-to-water ratio, residence time, and pretreatment method. The biocrude yields …

An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez

College of Graduate Studies: Theses & Dissertations

Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …

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 …

Molecular Modeling Of High-Performance Thermoset Polymer Matrix Composites For Aerospace Applications, Prathamesh P. Deshpande

Dissertations, Master's Theses and Master's Reports

The global efforts from major space agencies to transport humans to Mars will require a novel lightweight and ultra-high strength material for the spacecraft structure. Three decades of research with the carbon nanotubes (CNTs) have proved that the material can be an ideal candidate for the composite reinforcement if certain shortcomings are overcome. Also, the rapid development of the polymer resin industry has introduced a wide range of high-performance resins that show high compatibility with the graphitic surface of the CNTs. This research explores the computational design of these materials and evaluates their efficacy as the next generation of aerospace …

Recycled Printer Filament, Charlotte Hyland, Troy D. Molinar

Williams Honors College, Honors Research Projects

The purpose of this research is to examine the effects of recycling PLA filament for 3D printing on its material properties. After examining these effects, PLA and carbon fiber additives were mixed with recycled PLA pellets in different ratios to attempt to regain material properties lost in the recycling process. To complete these findings, an experiment was design and executed.

The research found that tensile strength during multiple iterations of recycling remained mostly unaffected, however, the strain degraded exponentially. In the PLA additive study, high ratios of PLA additive were able to increase the strength and strain properties of the …

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

Graduate Theses and Dissertations

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

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

Thinking Matters Symposium

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

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

Dissertations and Theses

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

The Critical Role Of Dynamic Surface Tension Of Surfactants On The Impact Dynamics Of Water Droplets, Amir Esmaeili, Reza Mohammadi

Graduate Research Posters

Due to their time-dependent surface tension, the addition of surface-active agents or surfactants to water for specific applications has made controlling the impact dynamics of these droplets a complex phenomenon. This work investigates the influence of the molecular weight, concentration, and ionic nature of the surfactants as well as the substrate surface characteristics on the impact dynamics of surfactant-laden droplets using a high-speed camera at 10000 frames per second. Sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, and n-decanoyl-n-methylglucamine were used as anionic, cationic, and nonionic surfactants, respectively. We used hydrophilic glass slides, hydrophobic polytetrafluoroethylene, and superhydrophobic alkyl ketene dimer (AKD) as substrates. …

Modulating Mechanical Properties Of Polymer Composites Via Colloidal Particle Reinforcement, Yusheng Guo

LSU Master's Theses

Additive manufacturing allows the rapid process of complex objects with excellent design flexibility. However, the products often exhibit poor mechanical properties when pure polymer is applied as printable material. In this work, we demonstrate that printability of polymer can be dramatically improved when particle filler is added to form reinforced polymer composites. Furthermore, the interaction between filler and polymer matrix leads to the enhancement in mechanical properties of the printed product. The material reinforcement induced by addition of fillers enables the wide application of polymer composites to print structures with unique features. In the printing of silica-reinforced pNIPAM composite, we …

Zips Precious Plastics: Plastic Extruder, Patrick Cole

Williams Honors College, Honors Research Projects

This project's goal was to design and build an affordable desktop filament extruder that can precisely and consistently extrude filament to a certain tolerance acceptable for 3D printers using wasted printing material. The group is partnering with an on campus organization focusing on engineering applications for sustainable futures. Zips Precious Plastics is a student run design group that intends to bring an innovation space on campus to help educate students about the importance of a closed looped system within plastic manufacturing.

A Foundational Approach To Extrusion And Compounding, David Frankart

Williams Honors College, Honors Research Projects

With a history of nearly 200 years, polymer processing and compounding is constantly changing to fit the material science needs of the era. Exposure of undergraduate students to the technology and practices used in industry today in a lab setting would create new opportunities for experiential learning and growth. The objective was to set up a 0.75”, 25 L/D Thermo Haake single screw extruder for lab use and run trials of material in a single screw extruder to set up a basis for experiments. Trials were run of co-polyester resin through a single screw extruder with carbon fiber additives varying …

Non-Einstein Viscosity Phenomenon Of Acrylonitrile–Butadiene–Styrene Composites Containing Lignin–Polycaprolactone Particulates Highly Dispersed By High-Shear Stress, Sing-Hoon Kim, Kisuk Choi, Kyouk Ryeol Choi, Taesung Kim, Jonghwan Suhr, Kwang Jin Kim, Hyoung Jin Choi, Jae-Do Nam

Mechanical Engineering Faculty Research

Lignin powder was modified via ring-opening polymerization of caprolactone to form a lignin–polycaprolactone (LPCL) particulate. The LPCL particulates were mixed with an acrylonitrile–butadiene–styrene (ABS) matrix at an extremely high rotational speed of up to 3000 rpm, which was achieved by a closed-loop screw mixer and in-line melt extruder. Using this high-shear extruding mixer, the LPCL particulate size was controlled in the range of 3395 nm (conventional twin-screw extrusion) down to 638 nm (high-shear mixer of 3000 rpm) by altering the mixing speed and time. The resulting LPCL/ABS composites clearly showed non-Einstein viscosity phenomena, exhibiting reduced viscosity (2130 Pa·s) compared to …

Electrochemical Hydrogenation Of Acetone To Produce Isopropanol Using A Polymer Electrolyte Membrane Reactor, Chen Li, Ashanti M. Sallee, Xiaoyu Zhang, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

Electrochemical hydrogenation (ECH) of acetone is a relatively new method to produce isopropanol. It provides an alternative way of upgrading bio-fuels with less energy consumption and chemical waste as compared to conventional methods. In this paper, Polymer Electrolyte Membrane Fuel Cell (PEMFC) hardware was used as an electrochemical reactor to hydrogenate acetone to produce isopropanol and diisopropyl ether as a byproduct. High current efficiency (59.7%) and selectivity (>90%) were achieved, while ECH was carried out in mild conditions (65 degrees C and atmospheric pressure). Various operating parameters were evaluated to determine their effects on the yield of acetone and …

Interface Model Of Pem Fuel Cell Membrane Steady-Dtate Behavior, Russell L. Edwards, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

Modeling works which simulate the proton-exchange membrane fuel cell with the computational fluid dynamics approach involve the simultaneous solution of multiple, interconnected physics equations for fluid flows, heat transport, electrochemical reactions, and both protonic and electronic conduction. Modeling efforts vary by how they treat the physics within and adjacent to the membrane-electrode assembly (MEA). Certain approaches treat the MEA not as part of the computational domain, but rather an interface connecting the anode and cathode computational domains. These approaches may lack the ability to consistently model catalyst layer losses and MEA ohmic resistance. This work presents an upgraded interface formulation …

Drawing And Twisting Of Graphene Fibers, Gregory T. Lane, Robert J. Sekerak, Isaias Diaz

Mechanical Engineering

The aim of this project was to develop a more automated process for drawing and twisting of graphene fibers than was currently in place. This was implemented by having two chemical baths with variable speed rollers at either end, and intermediate roller to spool fiber between stages, and a twisting cylinder with integral spool to twist the fiber as it is collected. The goal was to have this first iteration deliver a working prototype, however due to manufacturing delays and timing constraints, that will be missed. A second follow-on project would be able to continue the work presented here and …

The Development Of A Laminated Copolyester Electric Guitar, Addison S. Karnes

Electronic Theses and Dissertations

This thesis is an investigation of the fabrication and assembly methodologies employed in the development of a proof-of-principle prototype electric guitar composed of laminated copolyester. The objective of the project was to develop the processes and procedures to create an optimized physical and visual bond between layers to minimize vibratory dissipation, thus maximizing sustain. A high speed CNC router, abrasive waterjet, laser engraver-cutter, as well as various manual fabrication and assembly methods were investigated in the construction of the guitar prototypes. The lamination processes explored include low-temperature, heat-assisted pressure bonding, solvent and chemical welding, and contact adhesives. The project concluded …

Electrospinning Applications Air Filtration And Superhydrophobic Materials, Negar Ghochaghi, Adetoun Taiwo

Graduate Research Posters

Electrospinning is a widely applicable technique that generates non-woven fibers in the micro and nano range. In this project two of its applications are highlighted namely filtration media and enhancement of wettability. The first project demonstrates that electrospinning can be used to produce new fiber filtration media with controlled microstructure. The bimodal and unimodal orthogonal and random filters were made and characterized against their filtration efficiency and pressure drop. Figure of Merit (FOM) was also calculated and discussed. It is shown that the FOM increases when the electrospun fibers are arranged into alternating layers of aligned course and fine fibers. …