Pressure dependence of the pitch of cholesteryl oleyl carbonate

Abstract

Pollmann and Stegemeyer1 have shown that the pitch of a cholesteric mixture of cholesteryl oleyl carbonate (COC) and cholesteryl chloride (CC) increases very rapidly with pressure, approaching infinity at a critical pressure pc whose value depends on the composition of the mixture. At first sight, this result is surprising as one would anticipate only slight "red shift" when the sample is compressed. The aim of this note is to show that the observed critical divergence is in fact to be expected from theoretical considerations.