Influence of molecular structure on the cholesteric liquid crystalline behaviour of ethyl-cyanoethyl cellulose/acrylic acid solutions

Abstract

The liquid crystalline behaviour of (E-CE)C/AA solutions is connected with the (E-CE)C molecular structure and it was found that the critical concentration C ₁ at which the cholesteric phase begins to appear decreases with increase in both (E-CE)C molecular mass and the degree of substitution with cyanoethyl. The pitch of the cholesteric phase decreased with increasing (E-CE)C/AA concentration, and was not influenced by the (E-CE)C molecular mass. The pitch, however, was dependent on the (E-CE)C molecular mass and the degree of substitution with cyanoethyl. It increased with increasing (E-CE)C molecular mass when the degree of substitition with cyanoethyl was unchanged. It decreased and then increased with increasing degree of substitution with cyanoethyl when the (E-CE)C molecular mass was unchanged. There was a minimum value of the pitch when the degree of substitution with cyanoethyl was about 0.25.