Papers by Author: Neil John Coville

Abstract: This paper contributes to the body of knowledge on the efforts to develop nanodielectrics as the next generation of insulation material. The time-to-failure under electrical tree-induced degradation of 1.09-1.35 vol.% hexagonal BN/Epoxy was found to be 3 times longer than in clean epoxy. For 0.31-0.33 vol.% CNS/Epoxy the time-to-failure was 24 times longer than the clean epoxy. The electrical treeing partial discharge behaviour in the BN/Epoxy and CNS/Epoxy showed distinct time-evolution characteristics different from those in the clean epoxy. The improved electrical tree endurance in BN/Epoxy relative to the clean epoxy can be attributed to increased mechanical stiffness. The superiority of the CNS/Epoxy as a nanodielectric is notable. The effect is suggested to be due to the electron affinity properties of the carbon nanospheres at appropriate dispersion levels.

Abstract: Nanomaterials are of great importance for their versatile applications in gas sensors, solar cells and photocatalysis due to their unique optical, electrical and catalytic properties. Titania derived nanotubular and nanospherical particles with a titanate structure were synthesized using a hydrothermal procedure in the presence of very concentrated solutions of KOH and NaOH respectively. Both nanostructures were found to exhibit relatively large specific surface areas, i.e. 280 and 303 m2/g for materials treated in NaOH and KOH respectively. The morphological and structural properties were characterised by TEM, SEM, Raman spectroscopy and XRD.