Conformational volume in statistics of chain molecules

Abstract

The conformational volume V, represents a contribution to the partial molar volume Vof solutes which arises due to the non-identical volume of conformers in chain molecules. The paper presents expressions for calculations of the term V, based on the matrix method of conformational statistics. Starting from literature data on the volume differences in conformational diads, the con formational volume of poly(methy1ene) was calculated as a function of temperature and pressure. The combination of the results calculated with experimental data for nonane shows that the conformational term amounts to about 2% of the value of r a n d several percent in the temperature coefficient ofThe theory of the conformational volume is presented as a generalization of existing empirical additive schemes for the calculation of the partial molar volume of linear-chain solutes.