Engineering Commons^™

Sequence Effects On The Glass Transition Temperature, William Drayer

Williams Honors College, Honors Research Projects

Lithium ion batteries are widely used for the energy needs of portable electronic devices. Unfortunately, current liquid organic solvents used as the electrolytic portion of the battery have low thermal stability, resulting in batteries that may combust upon failure. This flammability can be attributed to the configurational strain in cyclic organic electrolytes. Due to the lack of configurational strain in a flexible polymer chain, designing polymer electrolytes for use in lithium ion batteries may result in a safer battery due to their lower flammability in comparison to traditional liquid organic electrolytes. From the perspective of an electrolytic polymer, lowering the …

Development Of Entubulation Strategies For Treating Central Nervous System Injuries, Ivy Brosch

Williams Honors College, Honors Research Projects

According to the McKnight Brain Institute, at least 10,000 people annually in the USA suffer from a central nervous system (CNS) injury. These injuries can cause serve disabilities including paralysis. Due to the complexity of the spinal cord, it is common that potential CNS treatments are first applied to an optic nerve crush (ONC) model in rats. Two proposed treatments were employed; one where nerve growth factor (NGF) was immobilized to a chitosan substrate to stimulate axonal regeneration, and the other using pentadecafluorooctanoyl chloride modified methacrylamide chitosan (MAC(Ali15)F) hydrogel to enhance local oxygenation. The two different treatments were formed into …

Vanadium Redox Flow Batteries: Design And Experimentation, Matthew George

Williams Honors College, Honors Research Projects

Vanadium flow batteries (VFB) are a type of battery that has potential as a grid-scale energy storage solution. An original design for a lab-scale VFB is presented herein, along with a procedure for electrolyte preparation from V₂O₅ using oxalic acid. The flow cell is constructed from Delrin, Teflon, Kynar, Santoprene, Nafion, graphite plate, and porous carbon. Two diaphragm pumps along with polyethylene, PVC, and Santoprene tubing are used. The active area is 58 cm². The battery was charged using a DC power supply at a constant current of 4 A with corresponding initial voltage of …

Galvanic And Pitting Corrosion Of A Fastener Assembly, Julie Shallman

Williams Honors College, Honors Research Projects

This research focuses on coupled galvanic/pitting corrosion of AA7075 when combined with stainless steel in a fastener assembly. A one-dimensional mathematical model of a well-mixed thin film electrolyte is developed to predict the damage profile of the AA7075 surface when its protective coating is damaged. The damage exposes the galvanic couple. A time dependent system of partial differential equations for potential, chloride concentration, aluminum ion concentration, and damage is developed and solved numerically. Two approaches to calculate the current density within aluminum pits are discussed. The first is a current balance between the cathodic, anodic and passive portions of the …

Molded Features In Pdms For Fabricating Bacterial Cellulose For Various Geometries, Mitchell Habegger

Williams Honors College, Honors Research Projects

The purpose of producing features on bacterial cellulose (BC) is to facilitate the elongation and alignment for cells, in this case Normal Human Dermal Fibroblast (NHDF) cells. The elongated cells have applications in wound healing, tissue engineering, disease diagnostics, and many other fields. Experiments were run to test the effectiveness of transferring features to BC sheets from features induced by fracturing on polydimethylsiloxane (PDMS) and those duplicated from molds with existing features. The features were duplicated to BC sheets by either air drying or Guided Assembly-Based Biolithography (GAB). The research results showed that fracture inducing on PDMS produced very small …

Sweat Sensor Modelling, Katie Brumbaugh

Williams Honors College, Honors Research Projects

There are no in-situ electrolyte sodium sensors available in the marketplace, however there is a demand and use for them. An in-situ sodium sensor can be used to monitor bodily functioning in many applications like medical patient monitoring and athlete monitoring during workouts. Patients with cystic fibrosis attempt to monitor salt content in sweat to maintain homoeostatic body function, this sweat sensor would change the way those patients took care of themselves [1]. Sweat sensor samples were made using multiwalled carbon nanotubes (MWNT) and nylon 6. The MWNTs were functionalized on the nylon using cyclo-oligomeric calixarene [3]. In functionalizing the …

Residence Time Distribution Of Mixing Based On Mathematical Modeling, Michelle Ayers

Williams Honors College, Honors Research Projects

Two different mathematical models were investigated for their use in describing the residence time distribution (RTD) of an industrial mixer. The first model investigated was the tanks-in-series model, while the second model was a combination of two branches of tanks-in-series. The tanks-in-series model is capable of characterizing the mixing present in the flow, but cannot detect non-idealities in flow such as bypassing and dead space. The multi-branch model has mathematical complexity, but it uses the second branch of flow to detect the presence of this non-ideal flow, determine if it is dead space of bypassing, and characterize how well-mixed the …

Evaluation Of Silane-Doped Epoxy Coatings For Resisting Aluminum Corrosion By Oxalic Acid, An A. Niger Metabolite, Alex Pica

Williams Honors College, Honors Research Projects

The goal of this study was to investigate whether silane-doped epoxy coatings are capable of preventing corrosion of aluminum alloy 2024-T3 by oxalic acid, one of the primary metabolites of the fungus Aspergillus Niger. Previous research suggested the success of these types of coatings at preventing AA 2024-T3 corrosion in saline solutions, and this study was meant to build on those findings by investigating the efficacy of the coating in an acidic environment.

Each coating was applied to an AA 2024-T3 coupon by dissolving the epoxy and varying amounts of 3-aminopropyltriethoxysilane in acetone and then dripping the solution onto …

Investigation Of Scanning Kelvin Probe Techniques, Nicholas D'Angelo Jr., Hongbo Cong

Williams Honors College, Honors Research Projects

The original scope of this work was to advance the understanding of corrosion properties of additively manufactured (AM) materials by correlating microstructural defects in AM materials to the material conventional counterparts utilizing a scanning kelvin probe [Ametek VeraSCAN Electrochemical System]. However, upon the initiation of project research, it was observed that the system was not operational due to unknown hardware and software problems. The evolved scope of this work was to reconcile the operational issues and develop a repair and mitigation plan. After extensive troubleshooting, it was determined that the software was not properly configured, and the electrometer had permanently …

Reaction Kinetics Of The Hydrogenation Of Phenol In A Tubular Reactor, Michael Selzer

Williams Honors College, Honors Research Projects

The reaction kinetic parameters for the hydrogenation of phenol to cyclohexanone are determined for the liquid phase reaction with the palladium catalyst supported on an electrospun PVDF membrane. Runs of the reactor were completed at catalyst loadings of 40, 50, and 60 g/m², and tube diameters of 0.187 in and 0.25 in with a runtime of ten hours. One-dimensional and two-dimensional models of the experimental setup were developed. Fitting data to the one-dimensional model found that the pre-exponential factor was 2.50 x 10⁴, the activation energy was 7.69 kJ/mol, and the order with respect to phenol …

Polyhexamethylene Biguanide Release By Chitosan-Heparin Nanoparticles, Jacob Ress

Williams Honors College, Honors Research Projects

Chitosan and heparin were used to synthesize nanoparticles using polyelectrolyte complexation. The optimal mixing ratio was determined to be 1:4 by studying the particle characteristics of zeta potential and dynamic light scattering of the ratios 1:2, 1:3, 1:4, 1:5 and 1:6 (chitosan: heparin). The particles were loaded with the antibiotic polyhexamethylene biguanide (PHMB) and the release was measured over 335 hours using the dialysis membrane incubation method and detected via ultraviolet-visible (UV-Vis) spectroscopy. Around 80% of the encapsulated PHMB was released over the measured period. The goal of this part of the study was to determine the drug release behavior …

Environmentally Friendly Alternates To Chemlok 233 Adhesive Cement, Madeline M. Busch

Williams Honors College, Honors Research Projects

The purpose of this project was to determine and qualify suitable, environmentally friendly replacement(s) for the current Chemlok 233 adhesive cement used by UTC Aerospace. Chemlok 233 was discontinued by the manufacturer based on the availability of a hazardous solvent (Trichloroethylene – TCE). The Chemlok 233 Control and four Experimental alternates with similar properties were lab tested for adhesion strength in various UTC proprietary cement specifications. The specifications modeled Chemlok’s uses in the construction of pneumatic de-icers. Chemlok 2332 was selected for use in Cement A, and Chemlok 402 was chosen for use in Cement B based on their highest …

Correlation Of Electrospun Polyvinylpyrrolidone Fiber Mat Thickness With Basis Weight, Fiber Diameter, Pore Size Distribution, And Air Permeability, Leah Mcpherson

Williams Honors College, Honors Research Projects

This project developed correlations between electrospun polyvinylpyrrolidone fiber mat thickness, basis weight, fiber diameter, pore size, and air permeability. The hypotheses were thinner fibers produce thicker mats, pore size decreases with fiber diameter, pore size and permeability decrease as basis weight increases. Project results could be used for modeling or quality control purposes.

Fiber diameter distributions were analyzed using a Scanning Electron Microscope and FibraQuant 1.3 software. Four conditions were chosen for further study: 0.284 ± 0.104 µm, 0.379 ± 0.128 µm, 0.520 ± 0.138 µm, and 0.733 ± 0.177 µm. Lower PVP concentrations produced thinner fibers.

Sample thickness (nm) …

Interfacial Corrosion Of Copper And The Formation Of Copper Hydroxychloride, Mary Teague, Shengxi Li, Hongbo Cong

Williams Honors College, Honors Research Projects

Electrical circuitry is an industry, among many others, heavily using the element of copper. Ensuring the mechanical integrity of Cu is crucial, especially in salt environments, for the multifaceted composition of circuits. 4N NaCl solution (equilibrium concentration in ~84% RH) simulated this three-phase system. Rectangular Cu samples were partially immersed in both ambient and continuous lab air sparging atmospheres to understand waterline corrosion of the metal. Open circuit potentials (OCP) were continuously taken during the immersion testing for a maximum of 5 days. A scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS), Raman spectroscopy, and 3-D …

Modeling The Effect Thickener Structure Has On The Oil Release Of Grease, Dana Cressman

Williams Honors College, Honors Research Projects

Our hypothesis was that the thickener type and micelle concentration of grease affected its viscoelastic properties. Measurements were made using a TA AR G2 rheometer and calculations were made using TA rheometer analysis software to characterize the viscoelastic response of grease under oscillatory shear and frequency tests. The oscillatory frequency tests determined the critical micelle concentration. The oscillatory stress tests were taken at temperatures from 5 to 65 degrees Celsius to create a master curve based on time temperature superposition of the measurements. The crossover points of G’ and G” on the oscillatory stress tests demonstrated where the grease transitions …

Tandem Mass Spectrometry (Ms/Ms) For Determination Of Architecture Of Synthetic Polymers, Shoumik Saha

Williams Honors College, Honors Research Projects

Tandem Mass Spectrometry (MS/MS) was used to determine the architecture of synthetic polymers and they are difluorene-N₃, 3-difluorene-N₃ and VPOSS-3-difluorene. VPOSS materials usually exhibit electrochemical properties and the research was performed to determine their accurate structure and to provide evidence of their proper synthesis. The compounds were mixed with a matrix solution, DCTB, and a silver salt to enable proper protonation. The solvent mixture was on a MALDI plate and then put into the mass spectrometer. The mass spectrum generated was analyzed and each fragment was identified to structures with the synthetic polymers via ChemDraw. Thus, trial …

Effects Of Hofmeister Ions On Gelation Of Gelatin And Pluronic Hydrogels, Eric Britton

Williams Honors College, Honors Research Projects

The purpose of the project was to observe the effects of the Hofmeister series of ions on the gelation of gelatin and Pluronic-127 hydrogels. Hydrogels are semi-solid materials that contain a network of joined molecules through intermolecular interactions which are capable of holding water. Gelatin and Pluronic-127 (PF-127) are thermoreversible, physical crosslinked gels. Gelation occurs when temperature, or other driving forces, reduce the polymer chain solubility until a distinct 2-phase system forms. When aqueous ions are present in solution, they exhibit specific ion effects that have either a stabilizing or destabilizing effect on the solubility of proteins and other polymers. …

Electrospinning Aqueous Solutions Of Poly(Ethylene Oxide) Using A Corona-Type Apparatus, Nicholas Neill

Williams Honors College, Honors Research Projects

The purpose of this project was to evaluate working parameters for the corona spinneret to create electrospun fibers/ fiber mat. This project was set-up using a Box-Behnken design of experiment. The working parameters were investigated by performing the electrospinning process, altering the working conditions, collecting the electrospun fibers. The scope of this project includes three primary operational conditions: distance between the spinneret and the collection plate, the viscosity (weight percent) of PEO in the spinning solution and the weight percent of NaCl in the spinning solution. The distance between the spinneret and the collection plate were varied to 18 cm, …