Engineering Commons^™

Mesophase Pitch-Based Carbon Fiber And Its Composites: Preparation And Characterization, Chang Liu

Masters Theses

The objective of this study is to investigate the relationship among process, structure, and property of the UTSI pitch-based carbon fibers and optimize carbon fiber’s mechanical properties through the stabilization process. Various analysis techniques were employed throughout these investigations which include the Scanning Electron Microscope (SEM), optical microscope, Dia-stron system, MTS, and ImageJ.

Several fiber process techniques including fiber spinning, stabilization, and carbonization were explored to determine the effect of the thermal process on the fiber yield, fiber diameter, the sheath-core structure of stabilized fibers, the pac-man and hollow core structures of carbonized fibers, and the resulting mechanical properties of …

Formation And Characterization Of Polymerized Supported Phospholipid Bilayers And The In Vitro Interactions Of Macrophages And Fibroblasts., Jonathan Michael Page

Masters Theses

Planar supported, polymerized phospholipid bilayers (PPBs) composed of 1,2-bis[10-(2’,4’-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphocholine (bis-SorbPC or BSPC) were generated by a redox polymerization method. The PPBs were supported by a silicon substrate. The PPBs were characterized and tested for uniformity and stability under physiological conditions. The PPBs were analyzed in vitro with murine derived cells that are pertinent to the host response. Cellular attachment and phenotypic changes in RAW 264.7 macrophages and NIH 3T3 fibroblasts were investigated on PPBs and compared to bare silicon controls. Fluorescent and SEM images were used to observe cellular attachment and changes in cellular behavior. The PPBs showed much lower …

Methods For Characterizing Mechanical Properties Of Wood Cell Walls Via Nanoindentation, Yujie Meng

Masters Theses

Nanoindentation is a method of contacting a material whose mechanical properties are unknown with another material whose properties are known. Nanoindentation has the advantage of being able to probe a material’s microstructure while being sensitive enough to detect variations in mechanical properties. However, nanoindentation has some limitations as a testing technique due to the specific formation and structure of some biomaterials. The main objective of this research is to identify any factors that influence the nanoindentation measurement of wood cell walls (a typical biomaterial).

The function of the embedding media in describing the properties of wood cells is poorly understood. …

Investigation Of The Processing, Structure And Properties Of Poly(Phenylene Sulfide) (Pps) Melt Spun Fibers, Prabhakar Gulgunje

Doctoral Dissertations

Numerous publications are available on the structure and properties correlation of fibers spun from polymers with flexible chains such as polyethylene terephthalate (PET), nylon, polypropylene. Also considerable amount of work is reported in fibers spun from rigid rod polymers like poly(p-phenylene terephthalamide) due to their value in high performance fibers category. However, very limited literature is available on the structure-properties relationship in fibers manufactured from poly(phenylene sulfide) (PPS), a high performance polymer which possesses chain flexibility between above two classes of polymers. A few researchers have studied crystallization kinetics and the fibers by extruding the polymer using capillary rheometers. However, …

Molecular Simulations Of Adsorption And Diffusion In Metal-Organic Frameworks (Mofs), Ruichang Xiong

Doctoral Dissertations

Metal-organic frameworks (MOFs) are a new class of nanoporous materials that have received great interest since they were first synthesized in the late 1990s. Practical applications of MOFs are continuously being discovered as a better understanding of the properties of materials adsorbed within the nanopores of MOFs emerges. One such potential application is as a component of an explosive-sensing system. Another potential application is for hydrogen storage.

This work is focused on tailoring MOFs to adsorb/desorb the explosive, RDX. Classical grand canonical Monte Carlo (GCMC) and molecular dynamic (MD) simulations have been performed to calculate adsorption isotherms and self-diffusivities of …

Developing Chitosan-Based Biomaterials For Brain Repair And Neuroprosthetics, Zheng Cao

Masters Theses

Chitosan is widely investigated for biomedical applications due to its excellent properties, such as biocompatibility, biodegradability, bioadhesivity, antibacterial, etc. In the field of neural engineering, it has been extensively studied in forms of film and hydrogel, and has been used as scaffolds for nerve regeneration in the peripheral nervous system and spinal cord. One of the main issues in neural engineering is the incapability of neuron to attach on biomaterials. The present study, from a new aspect, aims to take advantage of the bio-adhesive property of chitosan to develop chitosan-based materials for neural engineering, specifically in the fields of brain …

Effect Of Chemicals And Binders On The Durability Of Flame Retardant Treated Cotton Nonwovens, Hatice Mercimek

Masters Theses

Cotton based highloft nonwovens have been used in consumer goods such as pillows, upholstered furniture and mattresses for years. Cotton provides comfort, soft hand and cost effectiveness to these products. In contrast to its desirable properties, cotton products have a higher proneness to burning and are characterized as highly flammable materials. During the last decade, the fire safety has been an important issue, and there has been increasing focus on approaches to reduce hazardous fire risks and effects. Incorporating flame resistant (FR) chemicals and fibers is one of the most effective methods to improve thermal resistance of cotton to ignition, …