Adsorption of polyatomics: theoretical approaches in model systems and applications

J. L. RICCARDO; F. ROMÁ; A.J. RAMIREZ PASTOR

INTERNATIONAL JOURNAL OF MODERN PHYSICS B

WORLD SCIENTIFIC PUBL CO PTE LTD

Lugar: SINGAPUR; Año: 2006 p. 4709 - 4778

0217-9792

The adsorption of polyatomics on one- and two-dimensional lattices is studied by combining theoretical modeling, Monte-Carlo (MC), simulations and their correspondencewith experimental results. In one dimension, the rigorous statistical thermodynamics ofinteracting chains has been presented. With respect to two-dimensional adsorption, sixdifferent models to study non-interacting adsorbates have been discussed: (i) an extension to two dimensions of the exact thermodynamic functions obtained in one dimension;(ii) the Flory–Huggins’s approximation and its modification to address linear adsorbates;(iii) the well-known Guggenheim–DiMarzio approximation; (iv) the fourth one is a newdescription of adsorption phenomena, based on Haldane’s fractional statistics; (v) theso-called Occupation Balance, based on the expansion of the reciprocal of the fugacity;and (vi) a simple semi-empirical model obtained by combining exact one-dimensionalcalculations and Guggenheim–DiMarzio approach. In addition, the statistical thermodynamics of interacting polyatomics has been developed on a generalization in the spiritof the Bragg–Williams and the quasi-chemical approximations. Comparison with MCsimulations and experimental adsorption isotherms are used to test the accuracy andreliability of the proposed models. Finally, applications to heterogeneous systems andmultilayer adsorption are discussed.