Christian Wohlfarth is associate professor for physical chemistry at Martin-Luther University Halle-Wittenberg, Germany. He earned his degree in chemistry in 1974 and wrote his Ph.D. thesis in 1977 on investigations of the second dielectric virial coefficient and the intermolecular pair potential, both at Carl Schorlemmer Technical University Merseburg. In 1985, he wrote his habilitation thesis, Phase Equilibria in Systems with Polymers and Copolymers, at the Technical University Merseburg. Since then, Dr. Wohlfarth’s main research has been related to polymer systems. Currently, his research topics are molecular thermodynamics, continuous thermodynamics, phase equilibria in polymer mixtures and solutions, polymers in supercritical fluids, PVT behavior and equations of state, and sorption properties of polymers, about which he has published approximately 100 original papers. He has written the following books: Vapor-Liquid Equilibria of Binary Polymer Solutions, CRC Handbook of Thermodynamic Data of Copolymer Solutions, CRC Handbook of Thermodynamic Data of Aqueous Polymer Solutions, CRC Handbook of Thermodynamic Data of Polymer Solutions at Elevated Pressures, CRC Handbook of Enthalpy Data of Polymer-Solvent Systems, CRC Handbook of Liquid-Liquid Equilibrium Data of Polymer Solutions, and CRC Handbook of Phase Equilibria and Thermodynamic Data of Copolymer Solutions. He is working on the evaluation, correlation, and calculation of thermophysical properties of pure compounds and binary mixtures resulting in 11 volumes of the Landolt-Börnstein New Series. He is a contributor to the CRC Handbook of Chemistry and Physics.