Structural study of Langmuir-Blodgett monolayers and multilayers of amylose-esters with various alkyl chains

Abstract

A series of amylose-esters with various side chain lengths was studied. Isotherms of the monolayers on the water surface were measured, and polarized IR measurements, small-angle X-ray scattering, and ellipsometric measurements were carried out in order to characterize the structure of the multilayers formed. Amylose-esters with short alkyl side chains appear to have a helical conformation on the water surface which can be transferred into multilayers. The amylose-palmitate ester, however, as an example of an amylose-ester with long alkyl side chains, can only be transferred into mulilayers when the degree of substitution is lower than about 2.3 and only then when the monolayer is in the liquid analogous state to some extent. Amylose-palmitate forms partly ordered Y-type multilayers with side-chains that have a preferential orientation perpendicular to the surface.