Engineering Commons^™

Surface Modification Of Nanoplatelets In Polymer Nanocomposites, Shailesh K. Shori

Theses and Dissertations

In polymer nanocomposites (PNCs), it is very important that the nanofiller (typically an inorganic) is well-dispersed in an organic polymer matrix. Optimal compatibility results in end-use products such as packaging materials with enhanced properties. In practice, however, this is challenging to achieve because “ideal” dispersions require the complete uniform separation, termed exfoliation, of the nanofiller within the matrix. As a result, different nanofillers including calcium niobate (CN) and montmorillonite (MMT) are first studied for their ability to exfoliate in aqueous suspensions by measuring the organic cation uptake. The cation exchange capacity, or CEC, determined that CN needs further work before …

Effects Of Vapor Grown Carbon Nanofibers On Electrical And Mechanical Properties Of A Thermoplastic Elastomer, Daniel Thomas Basaldua

Theses and Dissertations - UTB/UTPA

Carbon nanofiber (CNF) reinforced composites are exceptional materials that exhibit superior properties compared to conventional composites. This paper presents the development of a vapor grown carbon nanofiber (VGCNF) thermoplastic polyurethane (TPU) composite by a melt mixing process. Dispersion and distribution of CNFs inside the TPU matrix were examined through scanning electron microscopy to determine homogeneity. The composite material underwent durometer, thermal gravimetric analysis, differential scanning calorimetry, heat transfer, hysteresis, dynamic modulus, creep, tensile, abrasion, and electrical conductivity testing to characterize its properties and predict behavior. The motivation for this research is to develop an elastomer pad that is an electrically …

Fabrication And Testing Of Arabinan Cellulose Nanocomposites, Ross Johnson, Austin Rosso, Nick Semansky

Materials Engineering

Inspired by the structure and composition of cactus spines found in nature, arabinan-cellulose nanocomposites were fabricated into thin films and tested for mechanical stiffness. The composites consisted of varying amounts of nanocrystalline cellulose reinforcement suspended in an arabinan matrix. Both materials are polysaccharides and are known to be biodegradable and food safe. The thin film samples were tensile tested using a dynamic mechanical analysis machine both as-cast and after a heat-treatment. The heat treatment of the arabinan itself resulted in an order of magnitude increase in stiffness, while the cellulose reinforced composites increased roughly six fold. The arabinan-50 wt% cellulose …

Nanodiamond Based Composite Structures For Biosensing Applications, Pedro Javier Villalba

USF Tampa Graduate Theses and Dissertations

This dissertation presents the synthesis and application of nanodiamond based materials for electrochemical biosensors. In this research work, nanodiamond particles have been used to prepare doped and undoped nanocrystalline diamond films, and conducting polymer composites for enhanced biosensing. The performance of the synthetized materials towards sensing applications was evaluated against glucose amperometric biosensing. Besides, cholesterol biosensing was attempted to prove the capabilities of the platform as a generic biosensing substrate.

Biosensors have been proved to provide reliable detection and quantification of biological compounds. The detection of biological markers plays a key factor in the diagnosis of many diseases and, even …

Biomechanical Applications And Modeling Of Quantum Nano-Composite Strain Gauges, Taylor David Remington

Theses and Dissertations

Biological tissues routinely experience large strains and undergo large deformations during normal physiologic activity. Biological tissue deformation is well beyond the range of standard strain gauges, and hence must often be captured using expensive and non-portable options such as optical marker tracking methods that may rely upon significant post-processing. This study develops portable gauges that operate in real time and are compatible with the large strains seen by biological materials. The new gauges are based on a relatively new technique for quantifying large strain in real-time (up to 40 %) by use of a piezoresistive nano-composite strain gauge. The nano-composite …

Novel Nanostructured Titania And Titania Nanocomposites For Photovoltaics And Photocatalysis, Xinning Luan

LSU Doctoral Dissertations

With the consumption of energy continually increasing around the world and the main source of this energy, fossil fuels, slowly being depleted, the need for alternate sources of energy is becoming more and more pertinent. Demand for solar energy has experienced exponential increase over the last decade. Nanostructured TiO2 has attracted significant attention due to its nontoxicity, low cost and wide applications in photovoltaics and photocatalysis. This research is focused on novel synthesis and surface modification of TiO2 nanotube arrays for applications in advanced dye-sensitized solar cells (DSSCs) and efficient photocatalysis. The first part of this work entails fast synthesis …

Crack Self-Healing In Sic/Spinel Nanocomposite, Fariborz Tavangarian

LSU Doctoral Dissertations

Spinel is one of the best known and widely used ceramic materials. It has good thermal shock resistance, high chemical inertness in both acidic and basic environments, excellent optical and dielectric properties, high strength at both elevated and normal temperatures, and has no phase transition up to the melting temperature (2135°C). Spinel is used in the metallurgical, electrochemical, and chemical industrial fields. It has also found some applications in dentistry, catalyst supports, humidity sensors, reinforcing fibers, photoluminescent materials, etc. One of the limitations of spinel ceramic is its brittleness. Furthermore, at high temperature applications, a rapid heating or cooling can …