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Full-Text Articles in Physics

Holographic Liquid Crystal Devices, Kotakonda Pavani Jan 2009

Holographic Liquid Crystal Devices, Kotakonda Pavani

Doctoral

Liquid crystals have become natural candidates for use in electro-optic devices for their ability to change the orientation of the director with the application of an electric field, and exhibiting large range of refractive index. The aim of the work presented in this thesis is to fabricate liquid crystal optoelectronic devices such as electrically switchable liquid crystal diffraction gratings and polarization rotators by exploiting the holographic surface relief effect in photopolymer and by developing novel polymer dispersed liquid crystals (PDLCs). Alignment of liquid crystals is commercially achieved by creating grooves on a conducting layer such as polyimide or indium tin …


Quantitative Analyses Of Dispersion, Doping And Electronic Separation Of Single Wall Hipco Carbon Nanotubes, Priya Baskar Rao Jan 2009

Quantitative Analyses Of Dispersion, Doping And Electronic Separation Of Single Wall Hipco Carbon Nanotubes, Priya Baskar Rao

Doctoral

As prepared SWNTs are obtained in bundles with a mixture of both metallic and semi conducting tubes. For many specific applications, electronically separated single individual tubes are required and in order to reach these application criteria, the tubes should be processed. This thesis reports on a systematic exploration of methods to routinely process, electronically separate and characterise commercially available single walled carbon nanotubes (SWNTs). Commercially available HiPco SWNTs were dispersed in water with the assistance of 1 % by weight sodium dodecyl benzene sulphate (SDBS). The tubes were dispersed in the water surfactant system through the aid of sonication and …