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 …

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) …

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, …