Abstract

Abstract Esters of octadecanoic acid and three primary alcohols such as methanol, ethanol, and propanol were deposited on substrates of potassium chloride (KCl), mica and amorphous carbon film under vacuum. The surface morphology of their films was observed by transmission electron microscope. They grew epitaxially to form the rectangular crystals with lateral molecular orientations on KCl substrate. On the other hand, ester molecules tend to arrange normal to the surface of mica and amorphous carbon film and construct the molecular layers like to Langmuir-Blodgett films. The crystal axis relationship between esters and KCl(001) surface was followed; c-axisester is parallel to 〈110〉KCl direction and 〈110〉ester direction inclines with an angle of about ±16° corresponding to 〈110〉KCl. These molecules had resemble crystal structures with trans configuration in the ester moiety. The optimum temperatures of substrates in the former epitaxial growth exist and the temperature decreases in proportion to the chain length of alcohol group with the discrepancy of about 10 to 30 °C.

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