From car parking to protein adsorption: an overview of sequential adsorption processes

The adsorption or adhesion of large particles (proteins, colloids, cells,...) at the liquid-solid interface plays an important role in many diverse applications. Despite the apparent complexity of the process, two features are particularly important: (1) the adsorption is often irreversible on experimental time scales and (2) the adsorption rate is limited by geometric blockage from previously adsorbed particles. A coarse-grained description that encompasses these two properties is provided by sequential adsorption models whose simplest example is the random sequential adsorption (RSA) process. In this article, we review the theoretical formalism and tools that allow the systematic study of kinetic and structural aspects of these sequential adsorption models. We also show how the reference RSA model may be generalized to account for a variety of experimental features including particle anisotropy, polydispersity, bulk diffusive transport, gravitational effects, surface-induced conformational and orientational change, desorption, and multilayer formation. In all cases, the significant theoretical results are presented and their accuracy (compared with computer simulation) and applicability (compared with experiment) are discussed. (C) 2000 Elsevier Science B.V. All rights reserved.