Other Chemical Engineering Commons^™

Polymer Based Energy Storage And Thermal Management On Textile Devices, Wesley A. Viola

Doctoral Dissertations

Humans developed textiles to manage thermal energy transfer with the environment and support homeostasis in a wide range of climates. With the anticipation of wearable technologies to transform healthcare via early, pre-symptomatic detection of illness, there is now a demand for electrical energy storage to support such on-body devices. Finding energy materials to merge seamlessly with textiles is basic requirement to ensure widespread adoption of wearable health monitors. Here we use a vapor deposition process to conformally coat ordinary fabrics with the doped conjugated polymer poly(3,4 ethylenedioxythiophene) (PEDOT-Cl), a soft material which possesses electronic and redox capabilities. We demonstrate PEDOT-Cl …

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 …

Influence Of Mechanical Properties Of Paper Coating On The Crack At The Fold Problem, Seyyed Mohammad Hashemi Najafi

Electronic Theses and Dissertations

Paper coating layers are subject to various stresses and deformations in many converting processes such as calendering, printing, slitting, and folding of the paper. In some cases, products may crack during folding to generate a defect called cracking at the fold (CAF). The parameters that influence these defects are not well understood. The overall goal of this thesis is to better understand the CAF behavior as related to material properties of the coating layer.

A method was developed to produce free-standing pigmented coating layers thick enough to be tested in bending as well as tension. The mechanical properties of these …

Iron-Containing Nanoparticles For The Treatment Of Chrionic Biofilm Infections In Cystic Fibrosis, Leisha M. A. Martin

Nanoscience and Microsystems ETDs

Cystic fibrosis (CF) is the most common genetic disease resulting in the morbidity and mortality of Caucasian children and adults worldwide. Due to a genetic mutation resulting in malfunction of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, CF patients produce highly viscous mucus in their respiratory tract. This leads to impairment of the mucociliary clearance of inhaled microbes. In addition to reduced microbial clearance, anoxic environmental conditions in the lungs promote biofilm-mode growth of the pathogenic bacterial species Pseudomonas aeruginosa. Chronic infections of P. aeruginosa begin in early childhood and typically persist until respiratory failure and death result. The …

Towards Sustainable Production Of Chemicals And Fuels From The Fast Pyrolysis Of Waste Polyolefin Plastics, Ulises Gracida Alvarez

Dissertations, Master's Theses and Master's Reports

The increasing amount of plastic waste (PW) generation has become an important concern due to the leveled-off recycling rates. Therefore, governmental agencies around the world, including state governments in the United States, have proposed initiatives to minimize the amount of PW that is landfilled and encourage recycling or energy recovery. Circular economy is a strategy that attempts on reusing PW to produce new polymers while avoiding its disposal and the use of virgin material. Chemical recycling raises an interesting technology prospect due to the potential reduction of pollutant emissions and the establishment of a circular economy through the production of …

Adaption Of Catechol And Reversible Addition-Fragmentation Chain-Transfer (Raft) Chemistries For Water-Based Applications, Olabode Oyeneye

Electronic Thesis and Dissertation Repository

Incorporating the binding chemistry of catechol functionality with RAFT chemistry offers a facile and simplified approach for developing a suite of new 2D and 3D hybrid materials with tailored morphologies. Leveraging both chemistries by synthesizing catechol-end functionalized RAFT agents and catechol-containing monomeric species for RAFT (co)polymerization, this dissertation examined a new series of advanced materials that were designed for water-based applications including model flocculants, thermoresponsive hydrogels, adsorbents and underwater adhesives.

To prepare the RAFT agents, novel trithiocarbonates with several catechol end R groups (as postpolymerization anchors) were synthesized that differ in their carbonyl α-substituents (Dopa-CTAs). These materials were evaluated for …

Catalytic Conversion Of Fructose, Glucose And Industrial Grade Sugar Syrups To 5-Hydroxymethylfurfural, A Platform For Fuels And Chemicals, Sadra Souzanchi

Electronic Thesis and Dissertation Repository

5-hydroxymethylfurfural (HMF) as a versatile and polyfunctional compound derived from dehydration of biomass has attracted increasing attentions in research over the past decades. HMF is an important intermediate and platform chemical, which can be converted into different useful chemicals as well as the promising biofuels. It can be obtained from acid-catalyzed dehydration of different C₆-based carbohydrates such as glucose, fructose, sucrose and cellulose.

In this thesis, a cost-effective process for catalytic conversion of simple sugars (particularly glucose and fructose) and industrial grade sugar syrups to HMF was studied in a novel biphasic continuous-flow tubular reactor using inexpensive heterogeneous …

Carbon Nanoadditives To Enhance Latent Energy Storage Of Phase Change Materials, Shadab Shaikh, Khalid Lafdi, Kevin P. Hallinan

Kevin Hallinan

Latent energy storage capacity was analyzed for a system consisting of carbon nanoparticlesdopedphase changematerials (PCMs). Three types of samples were prepared by doping shell wax with single wall carbon nanotubes(SWCNTs), multiwall CNTs, and carbon nanofibers. Differential scanning calorimetry was used to measure the latent heat of fusion. The measured values of latent heat for all the samples showed a good enhancement over the latent heat of pure wax. A maximum enhancement of approximately 13% was observed for the wax/SWCNT composite corresponding to 1% loading of SWCNT. The change in latent heat was modeled by using an approximation for the intermolecular …

Tribological Performance Of Hybrid Filtered Arc-Magnetron Coatings: Part I: Coating Deposition Process And Basic Coating Properties Characterization, Vladimir Gorokovsky, Chris Bowman, Paul Gannon, David Vanvorous, Andrey Voevodin, Adam Rutkowski, Christopher Muratore, Richard Smith, Asghar Kayani, David Gelles, Vaithiyalingam Shutthanandan, Boris Trusov

Christopher Muratore

Aircraft propulsion applications require low-friction and wear resistant surfaces that operate under high contact loads in severe environments. Recent research on supertough and low friction nanocomposite coatings produced with hybrid plasma deposition processes was demonstrated to have a high potential for such demanding applications. However, industrially scalable hybrid plasma technologies are needed for their commercial realization. The Large area Filtered Arc Deposition (LAFAD) process provides atomically smooth coatings at high deposition rates over large surface areas. The LAFAD technology allows functionally graded, multilayer, super-lattice and nanocomposite architectures of multi-elemental coatings via electro-magnetic mixing of two plasma flows composed of different …

Progress In The Development Of Adaptive Nitride-Based Coatings For High Temperature Tribological Applications, Samir Aouadi, Brandon Luster, Punit Kohli, Christopher Muratore, Andrey Voevodin

Christopher Muratore

Adaptive tribological coatings were recently developed as a new class of smart materials that were designed to adjust their surface chemical composition and structure as a function of changes in the working environment to minimize friction coefficient and wear between contact surfaces. This paper provides an overview of the current research developments in this field, including: (1) Chameleon nanocomposite coatings which are produced by depositing a multi-phase structure whereby some of the phases provide mechanical strength and others are lubricious; (2) Micro- and nano-textured coatings which consist of hard nitride films with highly ordered micropores and nanopores that are subsequently …

Plasma Enhanced Surface Treatments Using Electron Beam-Generated Plasmas, Darrin Leonhardt, Christopher Muratore, Scott Walton, Robert Meger

Christopher Muratore

NRL has developed a ‘large area plasma processing system’ (LAPPS) utilizing a high energy (∼2 keV) modulated electron beam to drive the plasma ionization. This system has been shown to be (1) efficient at producing plasma in any gas composition, (2) capable of producing low temperature plasma electrons (9–10¹² cm⁻³) and (3) scalable to large area (square meters). In this work, the progress of a number of applications using LAPPS is discussed. Nitride growth in stainless steel was investigated, which demonstrated high rates (up to 20 μm/h^1/2) at low temperatures (≤462 °C). Complementary mass spectrometry …

Molybdenum Disulfide As A Lubricant And Catalyst In Adaptive Nanocomposite Coatings, Christopher Muratore, Andrey Voevodin

Christopher Muratore

Nanocomposite YSZ–Ag–Mo–MoS₂ coatings with different MoS₂ additions (0–100 at.%) were deposited with a hybrid pulsed laser/magnetron sputtering/filtered cathodic arc process. Wear testing was performed from 25 to 700 °C for each of the coatings. Electron microscopy and other characterization techniques were used to examine the surfaces and wear tracks of the coatings and to determine the mechanisms resulting in the measured tribological properties. Adaptive coatings containing 8 at.% MoS₂demonstrated a friction coefficient of 0.2 throughout the temperature range examined here, compared to 0.4 for YSZ–Ag–Mo with no MoS₂. Characterization of the YSZ–Ag–Mo–8% MoS_{2 …}

In Situ Studies Of Tic1−X N X Hard Coating Tribology, Marisa Rebelo De Figueiredo, Christopher Muratore, Robert Franz, Richard Chromik, Kathryn Wahl, Andrey Voevodin, Michel O'Sullivan, Markus Lechthaler, Christian Mitterer

Christopher Muratore

TiC1−x N x hard coatings present time-dependent tribological behavior with an initial running-in period (500–2000 cycles) marked by an elevated friction coefficient, followed by >10000 cycles with low-friction and wear at room temperature (RT) in ambient air. The mechanisms behind this behavior are not completely understood. Tribological tests performed at RT and at different relative humidity (RH) levels revealed that a minimum value between 15 and 25% RH is needed to trigger the low-friction regime at a sliding speed of 100 mm s−1. By in situ observations of transfer film growth, it could be observed that third body material …

Adaptive Nanocomposite Coatings With A Titanium Nitride Diffusion Barrier Mask For High-Temperature Tribological Applications, Christopher Muratore, Jianjun Hu, Andrey Voevodin

Christopher Muratore

Adaptive nanocomposite coatings that demonstrate low friction throughout broad ranges of temperature, wear, humidity and other environments are currently in development. One effective temperature adaptation mechanism at temperatures ≤ 500 °C is diffusion of noble metal to the coating surface, providing a low shear strength interface at the friction contact supported by a hard surface underneath. To prolong the wear lifetime of chameleon coatings relying upon this mechanism for low friction, a coating architecture incorporating a diffusion barrier mask to inhibit noble metal diffusion was employed. The diffusion barrier-capped coating provided lubrication at 500 °C over ten times longer than …

A Simultaneous Increase In The Thermal And Electrical Transport In Carbon Nanotube Yarns Induced By Inter-Tube Metallic Welding, Sabyasachi Ganguli, Amber Reed, Chaminda Jayasinghe, Joe Sprengard, Ajit Roy, Andrey Voevodin, Christopher Muratore

Christopher Muratore

Vertically aligned arrays of multiwall carbon nanotubes (MWCNT) were decorated with gold (Au) nanoparticles of different diameter and areal densities and spun into yarns. The melting point of Au nanoparticles determined by differential scanning calorimetry was approximately 260 °C, well below the oxidation temperature of carbon. A continuous yarn was formed while pulling out a bundle of CNTs from the metalized CNT array. Relatively low temperature (300 °C) thermal processing of the metalized yarn resulted in a 30% improvement in thermal conductivity, 40% increase in electrical conductivity and a 4× increase in elastic modulus. Cross-sections of the yarn were examined …

Control Of Plasma Flux Composition Incident On Tin Films During Reactive Magnetron Sputtering And The Effect On Film Microstructure, Christopher Muratore, Scott Walton, D. Leonhardt, Richard Fernsler

Christopher Muratore

A hybrid plasma enhanced physical vapor deposition (PEPVD) system consisting of an unbalanced dc magnetron and a pulsed electron beam-produced plasma was used to deposit reactively sputteredtitanium nitride thin films. The system allowed for control of the magnitudes of the ion and neutral flux, in addition to the type of nitrogen ions (atomic or molecular) that comprised the flux. For all deposition experiments, the magnitude of the ion flux incident on the substrate was held constant, but the composition of the total flux was varied. X-ray diffraction and atomic force microscopy showed that crystallographic texture and surface morphology of the …

Temporally And Spatially Resolved Plasma Spectroscopy In Pulsed Laser Deposition Of Ultra-Thin Boron Nitride Films, Nicholas Glavin, Christopher Muratore, Michael Jespersen, Jianjun Hu, Timothy Fisher, Andrey Voevodin

Christopher Muratore

Physical vapor deposition (PVD) has recently been investigated as a viable, alternative growth technique for two-dimensional materials with multiple benefits over other vapor deposition synthesis methods. The high kinetic energies and chemical reactivities of the condensing species formed from PVD processes can facilitate growth over large areas and at reduced substrate temperatures. In this study, chemistry, kinetic energies, time of flight data, and spatial distributions within a PVD plasma plume ablated from aboron nitride (BN) target by a KrF laser at different pressures of nitrogen gas were investigated. Time resolved spectroscopy and wavelength specific imaging were used to identify and …

Control Of Plasma Flux Composition Incident On Tin Films During Reactive Magnetron Sputtering And The Effect On Film Microstructure, Christopher Muratore, Scott Walton, D. Leonhardt, Richard Fernsler

Christopher Muratore

A hybrid plasma enhanced physical vapor deposition (PEPVD) system consisting of an unbalanced dc magnetron and a pulsed electron beam-produced plasma was used to deposit reactively sputteredtitanium nitride thin films. The system allowed for control of the magnitudes of the ion and neutral flux, in addition to the type of nitrogen ions (atomic or molecular) that comprised the flux. For all deposition experiments, the magnitude of the ion flux incident on the substrate was held constant, but the composition of the total flux was varied. X-ray diffraction and atomic force microscopy showed that crystallographic texture and surface morphology of the …

Cross-Plane Thermal Properties Of Transition Metal Dichalcogenides, Christopher Muratore, Vikas Varshney, Jaime Gengler, Jianjun Hu, John Bultman, Timothy Smith, Patrick Shamberger, Bo Qiu, Xiulin Ruan, Ajit Roy, Andrey Voevodin

Christopher Muratore

In this work, we explore the thermal properties of hexagonal transition metal dichalcogenide compounds with different average atomic masses but equivalent microstructures. Thermal conductivity values of sputtered thin films were compared to bulk crystals. The comparison revealed a >10 fold reduction in thin film thermal conductivity. Structural analysis of the films revealed a turbostratic structure with domain sizes on the order of 5–10 nm. Estimates of phonon scattering lengths at domain boundaries based on computationally derived group velocities were consistent with the observed film microstructure, and accounted for the reduction in thermal conductivity compared to values for bulk crystals.

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 …

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, …

Minimizing Sheet Resistance Of Organic Photovoltaic Cell Top Contact Electrode Layer: Silver Nanowire Concentration Vs. Conductive Polymer Doping Concentration, Caitlyn Cook

Materials Engineering

The top contact electrode layers of nine organic photovoltaic cells were prepared with two varying factors: three Silver nanowire (AgNW) densities deposited on a conductive polymer doped with three concentrations. Silver’s low sheet resistance of 20-Ω/sq is hypothesized to lower the sheet resistance of the anode layer and thus enhance the overall efficiency of the cell. Four-point probe measurements indicated that increasing AgNW density in the top contact electrode layer of an organic photovoltaic cell significantly reduces sheet resistance from 52.2k-Ω/sq to 18.0 Ω/sq. Although an increase in doping concentration of the conductive polymer reduced sheet resistance in low AgNW …

Optimization Of Graphene-Based Materials Outperforming Host Epoxy Matrices, Liberata Guadagno, Marialuigia Raimondo, Luigi Vertuccio, Marco Mauro, Gaetano Guerra, Khalid Lafdi, Biagio De Vivo, Patrizia Lamberti, Giovanni Spinelli, Vincenzo Tucci

Chemical and Materials Engineering Faculty Publications

The degree of graphite exfoliation and edge-carboxylated layers can be controlled and balanced to design lightweight materials characterized by both low electrical percolation thresholds (EPT) and improved mechanical properties. So far, this challenging task has been undoubtedly very hard to achieve.

The results presented in this paper highlight the effect of exfoliation degree and the role of edge-carboxylated graphite layers to give self-assembled structures embedded in the polymeric matrix. Graphene layers inside the matrix may serve as building blocks of complex systems that could outperform the host matrix. Improvements in electrical percolation and mechanical performance have been obtained by a …

Computational Multiscale Modeling And Characterization Of Piezoresistivity In Fuzzy Fiber Reinforced Polymer Composites, Xiang Ren, Josh Burton, Gary D. Seidel, Khalid Lafdi

Chemical and Materials Engineering Faculty Publications

In this paper, the piezoresistive response (i.e. the change of resistance under the application of strain) of polymer composites reinforced by a novel material known as fuzzy fibers is characterized by using single tow piezoresistive fragmentation tests and modeled by using a 3D computational multiscale model based on the finite element analysis. In the characterization work, the fuzzy fiber tow is embedded in a dog-bone specimen infused by epoxy, with resistance and displacement measured simultaneously to obtain its piezoresistive response. An approximately linear and stable piezoresistive response is observed within the fuzzy fiber tow region yielding gauge factors on average …

Effect Of Nanofiber Morphology On Pvdf Air Filter Performance, Andrew W. Marton

Williams Honors College, Honors Research Projects

Poly(vinylidene fluoride) (PVDF) can be formed into small nanofibers by electrospinning that are useful for a variety of applications. Air filters produced with PVDF are known to capture ionic particles with high efficiency. Existing studies have focused on the effects of electrospinning conditions on nanofiber morphology. In this study fibers were generated with varying morphologies. Air filters were then made from each sample and then characterized by TSI. Air filters were found to have increased resistances relative to their capture efficiencies according to particle diameter. Capture efficiencies did not correlate strongly with particle diameter, and the presence of beads in …

The Future Of Carbon-Based Scaffolds In Foot And Ankle Surgery, Jarema S. Czarnecki, Khalid Lafdi, Panagiotis A. Tsonis

Chemical and Materials Engineering Faculty Publications

Autologous grafts have been the gold standard in tissue replacement and the most accurate means of recapitulating both the biological and mechanical properties of tissue. However, autologous grafts have had complications and drawbacks. Skin grafting, a prime example of an autologous tissue graft, has been limited by the size of graft, availability, and secondary donor site morbidity. Use of cadaveric tissues circumvents several limitations of autologous grafts; however, sterilization processes used to reduce the risk of disease transmission potentially weaken tissues and eliminate living cells and some growth factors from scaffolds, making them suboptimal tissue replacements. Chemical cross-linkage of tissue …

Temporally And Spatially Resolved Plasma Spectroscopy In Pulsed Laser Deposition Of Ultra-Thin Boron Nitride Films, Nicholas R. Glavin, Christopher Muratore, Michael L. Jespersen, Jianjun Hu, Timothy S. Fisher, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

Physical vapor deposition (PVD) has recently been investigated as a viable, alternative growth technique for two-dimensional materials with multiple benefits over other vapor deposition synthesis methods. The high kinetic energies and chemical reactivities of the condensing species formed from PVD processes can facilitate growth over large areas and at reduced substrate temperatures. In this study, chemistry, kinetic energies, time of flight data, and spatial distributions within a PVD plasma plume ablated from aboron nitride (BN) target by a KrF laser at different pressures of nitrogen gas were investigated. Time resolved spectroscopy and wavelength specific imaging were used to identify and …

Characterization Of Dimethyl Sulfoxide-Treated Wool And Enhancement Of Reactive Wool Dyeing In Non-Aqueous Medium, Luyi Chen, Bijia Wang, Jiangang Chen, Xinhui Ruan, Yiqi Yang

Department of Textiles, Merchandising, and Fashion Design: Faculty Publications

Wool pretreated with dimethyl sulfoxide (DMSO) was characterized and its dyeing behavior in non-aqueous green solvents was investigated. Reactive dyeing of wool in deep shades is challenging because the mandatory alkaline aftertreatment to match the fastness of mordant dyes inevitably causes damage to wool keratin. The current study showed that the colorfastness-integrity dilemma could be solved by replacing water with organic solvents as the dyeing medium. Covalent fixation is predominantly favored in solvent dyeing so that excellent colorfastness is achievable at any given shade without alkali aftertreatment. Compared with aqueous dyeing, solvent dyeing was found to give 30% higher covalent …

Effects Of Disorder State And Interfacial Layer On Thermal Transport In Copper/Diamond System, Vikas Sinha, Jaime J. Gengler, Christopher Muratore, Jonathan E. Spowart

Chemical and Materials Engineering Faculty Publications

The characterization of Cu/diamond interface thermal conductance (h_c) along with an improved understanding of factors affecting it are becoming increasingly important, as Cu-diamond composites are being considered for electronic packaging applications. In this study, ∼90 nm thick Cu layers weredeposited on synthetic and natural single crystal diamond substrates. In several specimens, a Ti-interface layer of thickness ≤3.5 nm was sputtered between the diamond substrate and the Cu top layer. The h_c across Cu/diamond interfaces for specimens with and without a Ti-interface layer was determined usingtime-domain thermoreflectance. The h_c is ∼2× higher for similar interfacial layers on …

Slow Release Of Ions From Internalized Silver Nanoparticles Modifies The Epidermal Growth Factor Signaling Response, Kristen K. Comfort, Elizabeth I. Maurer, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

Due to their distinctive physiochemical properties, including a robust antibacterial activity and plasmonic capability, hundreds of consumer and medical products contain colloidal silver nanoparticles (AgNPs). However, even at sub-toxic dosages, AgNPs are able to disrupt cell functionality, through a yet unknown mechanism. Moreover, internalized AgNPs have the potential to prolong this disruption, even after the removal of excess particles. In the present study, we evaluated the impact, mechanism of action, and continual effects of 50 nm AgNP exposure on epidermal growth factor (EGF) signal transduction within a human keratinocyte (HaCaT) cell line. After AgNP expose, EGF signaling was initially obstructed …