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Preface

Particle deposition on surfaces is a subject of both fundamental and practical interest. From a fundamental standpoint, studies of deposition under con- trolled conditions can give insight into the colloidal forces operating between particles and substrates and the role of hydrodynamics in particle transport and capture. Because, in principle, the nature of the substrate and of the par- ticles can be controlled independently, it is possible to systematically test cur- rent theories of heterointeractions in a manner which is not possible by stan- dard colloid stability approaches. So far, such tests have shown significant discrepancies between theory and experiment, which have not yet been en- tirely resolved.

In practice, particle deposition occurs in a very wide variety of systems and processes. Sometimes, deposition is desirable, as in the attachment of particles to sand grains in water filters, and of pigment particles to cellulose fibres in papermaking. In many other cases, attempts are made to prevent deposition as far as possible. These include the coating of coarse mineral particles by much finer particles (“slimes coating”) and the “fouling” of surfaces by un- wanted deposits. There are also very many biological examples such as bacte- rial adhesion. Much previous work in these areas has been of a rather empirical nature and there is a need for a better appreciation of the fundamental prin- ciples involved.

In September 1988, the Colloid and Surface Chemistry Group of the Society of Chemical Industry held an International Symposium at University College London on the subject of “Particle Deposition at the Solid-Liquid Interface”. This attracted papers from many world experts in the field, both on the fun- damental and applied aspects. Most of the papers presented are contained in this special issue of Colloids and Surfaces. The usual refereeing procedures have been applied. The papers provoked lively discussion, much of which is also included. The proceedings give an up-to-date account of current ideas in the field and point the way to a number of possible advances.

I would like to thank fellow members of the Organizing Committee, Dr Thar- wat Tadros and Dr Brian Vincent for their help and support, and the Confer- ence Office of SC1 for the efficient and friendly manner in which they attended to the arrangements for the Symposium.

John Gregory Symposium Chairman