Applied Clay Science, 2 (1987) 83-93 83 Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands Clay Particle Engineering: a Potential New Technology with Diverse Applications PAUL H. NADEAU Department of Mineral Soils, The Macaulay Institute [or Soil Research, Craigiebuckler, Aberdeen AB9 2QJ (Great Britain) (Received March 18, 1986; accepted after revision September 30, 1986) ABSTRACT Nadeau, P.H., 1987. Clay, particle engineering: a potential new technology with diverse applica- tions. Appl. Clay Sci., 2: 83-93. The ability to disperse different clay materials in aqueous suspensions into fundamental par- ticles 1-10 nm thick and combine them in various combinations and proportions has stimulated research into the more effective use of the unique properties of these materials. These properties include high surface area (up to 800 m2/g), cation exchange capacity (up to 120 meq./100 g) and anion exchange capacity (up to 25 meq./100 g) which can be utilized in a variety of industrial processes and other commerical applications. The products of such combinations are synthetic, randomly interstratified clays whose adsorption/desorption characteristics, micro-porosity, permeability, and interlayer chemistry can be modified to optimize their performance as chemical supports and heterogeneous catalysts. Thin films (10-100 nm ) can be formed from these materials with a wide range of compositions and properties with possible applications in the medical treat- ment of burns and wounds, as release agents and coatings in pharmaceuticals and agricultural products, for the immobilization of bacteria and as enzyme supports in biotechnology. The coat- ings and films can be fired at temperatures of 1000°C to produce micro-ceramic products which could lead to applications such as electrical insulators and semiconductors and as protective coat- ings and bonding intermediates in the material sciences. This report outlines the methods of preparation and properties of these clay materials and presents analytical and experimental results demonstrating the promise of this technology. CLAY SUSPENSIONS: PRECURSORS TO SYNTHETIC, RANDOMLY INTERSTRATI- FIED CLAYS The proper preparation of clay suspensions is required for the complete dis- persion of the clay material. These methods are the subject of British Patent Applications GB 2154998A, 8513050 (Nadeau, 1984, 1985a) and involve the saturation of expansible clay materials with either Na + or Li + cations in an aqueous medium followed by the removal of any excess ions by dialysis and extraneous material by centrifugation. The resulting suspensions usually have concentrations of 0.1% to 1% solids. Suspension concentration is determined 0169-1317/87/$03.50 © 1987 Elsevier Science Publishers B.V.