Studies on the surface micromorphology and surface conductivity in thin polymer films of poly vinyl alcohol (PVA) and poly ethylene oxide (PEO) in both as-grown and ion-implanted polymer films have been carried out to reveal certain specific features of the ordered state in these materials. Optical microscopic investigations revealed the existence and enhanced formation in number of spherulites and dendrites in ionimplanted films relative to the as-grown films. The number and rate of formation of spherulites indicated an increase in the degree of crystallinity in these films. Measurements of surface conductivity of as-grown and ion-implanted polymer films, employing four-point probe method, indicated a decrease in electrical conductivity on ion-implantation. Photomicrographic analysis of the PVA and PEO thin film surfaces, has enabled to propose a temperature-stress induced mechanism of crystallization in conjunction with the surface conductivity measurements. The decrease in surface conductivity on ion-implantation in both PVA and PEO thin films, is attributed to a decrease in mobility of macromolecular charged species due to an increase in degree of crystallinity as has been observed by optical microscopy.

2,4-Dihydroxybenmphenone oxime is found to undergo loss of OH., H,O, NHOH and PhCNO when subjected to electron impact, revealing novel hydrogen and skeletal migrations. The fragmentation mechanisms are found to differ considerably from those of benzophenone oxime and we confirmed these cleavages by exact mass measurements and deuterium labelling.

Experimental investigations on He + ion (150 keV) beam modifications of the (100) surfaces of ADP and KDP single crystals, relative to asgrown surfaces have been made, to assess the nature and extent of radiation damage. Studies on the surface micromorphology, defect substructure, defect concentration, surface conductivity and microhardness have been made. Studies on chemical etching in both ion irradiated and asgrown surfaces revealed drastic changes in etchpit morphology and defect concentration. Measurement of surface electrical conductivity, employing four-point probe method, showed enhancement in conductivity at all the temperatures of observation which is attributed to enhanced proton migration. Measurement of microhardness and studies on planar plastic anisotropy in asgrown surfaces relative to ion bombarded surfaces have been made employing Knoop indenter and the results are interpreted in terms of the nature of bonding, bond strength and radiation damage on ion bombardment. Plastic anisotropy in these surfaces is found to be in conformity with the (100) plane on which the indentations were made.

Die Alkylierung der Dibenzoylmethane (I) mit Dimethylsulfat (II) in siedendem Aceton in Gegenwart von Kaliumcarbonat führt zu den Dibenzoylethanen (III).

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