Original scientific paper

Adsorption of Nonspherical Particles at Solid/Liquid Interfaces

Zbigniew Adamczyk ; Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences 30-239 Cracow, ul. Niezapominajek 1, Poland
Paweł Weroński ; Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences 30-239 Cracow, ul. Niezapominajek 1, Poland

Abstract

Localized adsorption of nonspherical particles at solid/liquid interfaces was analyzed theoretically. Aproximate models for calculating interactions between particles and interfaces as well as between particles were discussed. It was demonstrated that for convex particles the Derjaguin model can be used for small separations, whereas for larger separations the equivalent sphere approach proved more appropriate. These analytical energy expressions were used in numerical Monte-Carlo RSA (random sequential adsorption) simulations of particle adsorption. Theoretical results concerning the blocking parameter (available surface function) and adsorption kinetics for short and long times were reported for prolate and oblate spheroids. Similarities and differences between flat (2D) and unoriented (quasi 3D) adsorption of particles were discussed and limiting power-law for the long-time regimes were specified. By extrapolation of the kinetic results the maximum (jamming) coverages for hard and interacting spheroids were determined. It was demonstrated that the jamming coverages under the conditions of unoriented adsorption exceed these of flat adsorption by many times for elongated objects. It was also demonstrated that the repulsive double-layer interactions decrease significantly the monolayer capacity of adsorbed layers of spheroidal particles. Implications of this phenomenon for protein adsorption were discussed.

Keywords

Hrčak ID:

132431

URI

https://hrcak.srce.hr/132431

Publication date:

1.12.1998.

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