Irreversible adsorption of colloidal particles on solid substrates

In this article, we summarize the basic results relative to the field of ir reversible deposition processes of colloidal particles on solid surfaces. A n irreversible deposition process is defined as a process in which, once ad sorbed, a particle can neither diffuse along, nor desorb from the surface. However, some extensions leading to reversible adsorption models are also o utlined. First the basic tools used in these studies are introduced, notabl y the concept of available surface function. General results relative to th ese processes are then presented. We discuss, in particular, the connection between the reduced variance of the number density fluctuations of adsorbe d particles and the available surface function. We then review the main mod els which were introduced in the literature to account for these processes. They can be divided in two classes: (i) the models which are based entirel y on statistical and geometrical grounds. The most widely studied of them i s the Random Sequential Adsorption (RSA) model which is discussed in detail . For the processes in which gravity plays an important role one uses the B allistic Deposition (BD) model. We also present models which are aimed at a ccounting for the behavior lying between the ballistic deposition and the R SA. (ii) The second type of models corresponds to those which take explicit ly the diffusion of the particles in the vicinity of the adsorption plane i nto account. The results relative to these models, called diffusional model s, are discussed in detail. Finally, the last part of the article is devote d to experimental results. We present and discuss in a critical way experim ental evidence which seems to indicate the validity of the RSA and ED model s. (C) 2000 Elsevier Science B.V. All rights reserved.