The Open Crystallography Journal

2011, 4 : 40-48
Published online 2011 July 26. DOI: 10.2174/1874846501104010040
Publisher ID: TOCRYJ-4-40

Effect of Electron Irradiation on the Thermodynamical and Optical Properties of Cholesteryl Pelargonate

Rohit Vermaa , R. Dhar , R. Dabrowski , M. C. Rath and S. K. Sarkar
Centre of Material Sciences, Institute of Interdisciplinary Studies (IIDS), University of Allahabad, Allahabad, India.

ABSTRACT

Thermodynamical and optical properties of pure and electron beam irradiated (20, 80 and 100 kGy doses) liquid crystalline material cholesteryl pelargonate (nonanoate) have been investigated by differential scanning calorimeter, polarized light microscopy and ultraviolet-visible spectroscopy. Transition temperatures, enthalpies and entropies are found to be lowered due to the irradiation. A donor-acceptor type charge transfer complex peak is observed besides the pure sample peak in the ultraviolet-visible spectra due to irradiation. The concentrations of impurities have been estimated by the area of the pure and charge transfer complex peaks besides using the Van’t Hoff equation. The concentration of impurity is found to increase linearly with the irradiation dose.

Keywords:

Electron beam irradiation, Differential Scanning Calorimeter, UV-Vis spectroscopy, Charge transfer complex, Van’t Hoff Equation.