A method for measuring osmotic pressure of low-molar-mass compounds in polymers

Abstract

Sorption combined with hydrostatic weighing is proposed as a method for the determination of osmotic pressure in dependence on temperature and hydrostatic pressure. By measuring changes in weight and volume of a polymer membrane one can determine the density of a mixture of vapour and liquid resulting from condensation. Formulae that relate the osmotic pressure and the entropy of the mixture have been derived. The reversibility of volume deformation in a swollen polymer has been checked.