Association probabilities between the single-chain amphiphiles into a binary mixture in plan monolayers (II).

Abstract

A test system of homologous binary mixtures of single-chain amphiphiles was considered. The dependence of the association probabilities on the hydrophobic chain length, and on the dipole moment of the shorter chain component when the longer chain component has a low dipole moment, was studied. The free-end effect of each hydrophobic chain on the association probability was also analysed. Generally, both the shorter chain end effect and the longer chain end effect on the association process are independent of their own initial chain length, but are dependent on the chain length of the other component and dipole moment. The changes in every association probability produced by the addition of one methylene group to the shorter chain and to the longer chain are unequal and opposite. For this reason the efficiency ratios were defined and analysed. The thermotropic behaviour of lipid mixtures can be related to association processes.