AbstractsEngineering

Van Der Waals Interactions Based Rheological Analysis for Electrosterically Stabilized Nano-Sized Alpha Silicon carbide-Lactobacillus Gg Dispersions

by Navin Jose Manjooran




Institution: Virginia Tech
Department: Materials Science and Engineering
Degree: PhD
Year: 2007
Keywords: Electron Microscopy; Shear Stress; Zeta Potential; Dispersant; Solids Loading; Dispersion; Viscosity; Rheology; Surface Forces
Record ID: 1799797
Full text PDF: http://scholar.lib.vt.edu/theses/available/etd-01312007-135910/


Abstract

Although enormous potential benefits are envisioned with the application of nanotechnology in conjunction with biological systems, interactions of nano particulate materials with biological materials is not well understood. The focus of this dissertation is to determine the mathematical relationships of the forces between nanoparticles and biological agents. The systems under investigation are the alpha-SiC/H2O/LGG polar based systems. The mathematical analysis for the surface forces, based on the attractive van der Waals forces for the alpha-SiC/H2O/alpha-SiC and alpha-SiC/H2O/LGG polar solvent based systems are presented and discussed. The rheological parameters including pH, zeta potential, shear rate, shear stress and viscosity that alter the dispersion mechanisms are also presented and discussed. The concurrence of the experimental analysis with the mathematical modeling is also presented. The rheological analysis in these systems for determining of the optimum amounts of dispersant, binder, plasticizer and solids loading using the Krieger-Dougherty fit and Liuâs model are presented and discussed. Alpha-SiC/H2O/alpha-SiC and alpha-SiC/H2O/LGG polar solvent based samples were also fabricated to test for an application area of nano-bio technology: A novel nano and micro porous materials fabrication process. Porous materials are used for a variety of applications including insulation, filtration, catalytic substrates, textiles and consumer goods and accounts for billions of dollars in sales annually. Results from the alpha-SiC/H2O/alpha-SiC and alpha-SiC/H2O/LGG polar solvent based slip and freeze cast samples and their characterization using digital and electron microscopy are presented and discussed. Finally, the green and sintered density, porosity and strength of the alpha-SiC/H2O/alpha-SiC and alpha-SiC/H2O/LGG polar solvent based dispersion samples are determined and discussed.