Not available / text

Surfaces with nanopatterned biological functionality are important prerequisites for many applications including developing biosensors, tissue engineering scaffolds and Bio-MEMS devices. This work presents a versatile technique, termed nanoscale orthogonal biofunctionalization imprint lithography, which allows "top-down" highprecision nanopatterning of proteins that can meet the demands of various applications. To show applicability of this technique, it was used to create disposable large scale arrays of nanopatterned cell adhesion proteins for cell culture for the purpose of investigating the influence of nanoscale geometrical parameters on cell-surface interactions. These cell culture arrays were used to systematically vary the size, spacing and density of fibronectin adhesion clusters, which are expected to modulate the signaling induced by the cell adhesion, the clustering of adhesion molecules and the force generated in the cytoskeleton. As a result, it was first determined that the nanopatterned adhesion sites provided an upper limit to the size of a corresponding cell focal adhesion. Cell morphology, actin stress fibers, vinculin distribution, proliferation and motility were all influenced by nanoscale fibronectin island size, and in some cases, the distance between patterns. Several parameters depended biphasically on the pattern size, indicating a very fine regulation of the associated cell signaling. Adhesion area and local stress on the adhesion are modulated by the adhesion size, and the cell response on the nanopattern shows strong parallels to the response on elastic adhesion substrates. In addition, chemical signaling may be influenced directly by changing the activity of associated enzymes. The results of this work build a basis for an understanding of adhesion on the nanoscale level and offer design criteria for the engineering of biomaterials and tissue scaffolds.

Not available / text

No description available.

<p>This work entails the preparation of various polyanilines with different morphologies and their application in photovoltaic solar cells. Zinc oxide (ZnO) with one-dimensional and flower-like morphology was also prepared by microwave irradiation and used as electron acceptors in photovoltaics devices. The morphological, structural, spectroscopic and electrochemical characteristics of these materials were determined by scanning electron microscopy (SEM), X-Ray diffraction (XRD), Raman, Fourier-transformed infrared spectroscopy (FTIR), ultraviolet and visible spectroscopy (UV-Vis), photoluminescence(PL), thermal gravimetric analysis (TGA) and cyclic voltammetry (CV) experiments. Devices fabricated from these materials were characterized under simulated AM 1.5 at 800 mW.</p>

<p>The objective of this research was to develop highly efficient and yet effective MnO2 electrode materials for supercapacitors applications. Most attention had focussed on MnO2 as a candidate for pseudo-capacitor, due to the low cost of the raw material and the fact that manganese is more environmental friendly than any other transition metal oxide system. The surface area and pore distribution of MnO2 can be controlled by adjusting the reaction time. The MnO2 synthesised under optimum conditions display high capacitance, and exhibit good cycle profile. This work investigates the ways in which different morphological structures and pore sizes can affect the effective capacitance. Various -MnO2 were successfully synthesised under low temperature conditions of 70 oC and hydrothermal conditions at 120 oC. The reaction time was varied from 1 to 6 hours to optimise the conditions. KMnO4 was reduced by MnCl.H2O under low temperature, whereas MnSO4.4H2O, (NH4)2S2O8 and (NH4)2SO4 were co-precipitated under hydrothermal conditions in a taflon autoclave to synthesise various -MnO2 nano-structures.</p>

Thesis (Ph. D.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 106-112).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of North Texas, May, 2007. / Title from title page display. Includes bibliographical references.