Molecular thermodynamics of flexible-molecule fluids

Some of the most important problems encountered -in the statistical-mechanical treatment of dense, complex molecular fluids are indicated. Particular attention is given to the application of the generalized van der Waals concept to flexible-molecule fluids. Perturbed-hard-chain theory and chain-of-rotators theory are reviewed. This is followed by a brief summary of recent experimental work on thermodynamic excess properties of liquid mixtures of type (Y + an n-alkane). Several novel effects connected with local correlation of molecular orientation in the n-alkanes, with medium-induced conformational changes and with preferential orientation of strongly polar molecules are discussed (order/disorder phenomena).