TY  - JOUR
A1  - Becker, Friedrich
A1  - Kiefer, Michael
A1  - Rhensius, Peter
T1  - Theoretische Behandlung flüssiger Mischungen mit Hilfe von Gleichgewichtsmodellen. Teil I: Binäre symmetrische Mischungen
T1  - Theoretical Treatment of Liquid Mixtures by Means of Equilibrium Models
T2  - Zeitschrift für Naturforschung, A
N2  - A thermodynamic theory of liquid mixtures based on a simple molecular model is developed which describes the equilibrium state as the result of a coupling between a "chemical" and a "statistical" equilibrium. The intermolecular interactions are taken into account by considering "complexes" formed between a given molecule and its z nearest neighbours. The equilibrium mole fractions of these complexes are calculated by application of the ideal law of mass action to an appropriate set of "exchange equilibria". Formulae for the excess functions GE and HE and for the activities of the components are derived for the cases z=1 and z=4. GE depends on an equilibrium constant K describing the deviation from random distribution of the equilibrium mole fractions of the complexes. HE depends on K and on an energy parameter w which is related to differences of pair interactions. K and w are independent parameters, and there is no limitation in respect to amount and sign of the excess functions. The conditions for the existence of a critical solution point are formulated; at this point GE has a value of about 0.56 R T. If a model with two equilibrium constants is used allowing for instance competition between "self-association" and "complex-formation", the existence of closed miscibility gaps becomes possible. Closed miscibility curves are calculated and the conditions for their appearance are discussed. The relations between this theory and Guggenheim's statistical lattice theory of symmetrical mixtures are pointed out.
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/74035
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-740350
SN  - 1865-7109
VL  - 27
IS  - 11
SP  - 1611
EP  - 1624
PB  - Verlag der Zeitschrift für Naturforschung
CY  - Tübingen
ER  -