The natural microporous materials include several types of minerals such as zeolites, clay minerals, micas, Fe-lMn- oxides/hydroxidesloxyhydroxides present in various geo- logical environments and soil formations. Their crystal structure is characterised by the presence of intra crystal micropores (channels or interlayer void spaces) providing high microporosity/surface area and distinguished physico-chemical properties such as cata- lytic and sorptivelion-exchange ones. This volume includes the key- lectures and participant contributions delivered at the NATO-funded Advanced Research Workshop on the Application of Natural Microporous Materials for Environmental Technology, which was held in the th Smolenice Castle, Slovakia, from the 2()1h to 30 of October 1998 and was attended by 55 participants from 17 countries. The purpose of the workshop was the critical assessment of the current developments and discussion of the future perspectives in the field of utilisation of natural microporous materials (zeolites, clays, oxides) for the solution of problems related to the toxic and nuclear waste management, water pollution control and decontamination, the environmental catalysis associated with atmospheric pollution, the creation of new materials for energy storage and agricultural management including the development of artificial soils for plant growth in the space. Of especial importance for this meeting was the exchange of information and know-how among specialists working in institutions of NATO and Cooperation Partner countries aiming towards the development of common strategies for the solution of environmental problems and the promotion of further scientific and technological collaboration in the field.

This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involve chemistry, physics, and engineering, with length scales ranging from Angstromsup to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area ofcurrent interest and brings together leading experts to give an up-to-date discussion of their work and the work ofothers. Each article contains enough references that the interested reader can accesstherelevant literature. Thanks aregiven to the Center forFundamental Materials Research atMichigan State University forsupportingthis series. M.F. Thorpe, Series Editor E-mail: [email protected] EastLansing, Michigan, September, 1995 PREFACE This book records selected papers given at an interdisciplinary Symposium on Access in Nanoporous Materials held in Lansing, Michigan, on June 7-9, 1995. Broad interest in the synthesis of ordered materials with pore sizes in the 1.0-10 nm range was clearly manifested in the 64 invited and contributed papers presented by workers in the formal fields of chemistry, physics, and engineering. The intent of the symposium was to bring together a small number ofleading researchers within complementary disciplines to share in the diversity of approaches to nanoporous materials synthesis and characterization."

The natural microporous materials include several types of minerals such as zeolites, clay minerals, micas, Fe-lMn- oxides/hydroxidesloxyhydroxides present in various geo- logical environments and soil formations. Their crystal structure is characterised by the presence of intra crystal micropores (channels or interlayer void spaces) providing high microporosity/surface area and distinguished physico-chemical properties such as cata- lytic and sorptivelion-exchange ones. This volume includes the key- lectures and participant contributions delivered at the NATO-funded Advanced Research Workshop on the Application of Natural Microporous Materials for Environmental Technology, which was held in the th Smolenice Castle, Slovakia, from the 2()1h to 30 of October 1998 and was attended by 55 participants from 17 countries. The purpose of the workshop was the critical assessment of the current developments and discussion of the future perspectives in the field of utilisation of natural microporous materials (zeolites, clays, oxides) for the solution of problems related to the toxic and nuclear waste management, water pollution control and decontamination, the environmental catalysis associated with atmospheric pollution, the creation of new materials for energy storage and agricultural management including the development of artificial soils for plant growth in the space. Of especial importance for this meeting was the exchange of information and know-how among specialists working in institutions of NATO and Cooperation Partner countries aiming towards the development of common strategies for the solution of environmental problems and the promotion of further scientific and technological collaboration in the field.

Polymer-clay nanocomposites are formed through the union of two very different materials with organic and mineral pedigrees. The hybrid compositions, however, exhibit large increases in tensile strength, modulus, and heat distortion temperature as compared with the pristine polymer. The composites also have lower water sensitivity, reduced permeability to gases, and a similar thermal coefficient of expansion. All of these property improvements can be realized without a loss of clarity in the polymer. Further, it has been found that nanocomposites impart a level of flame retardance and UV resistance not present in the pure polymer. These improvements in performance properties at relatively low clay loading (typically 2 -10wt %) have stimulated intensive research in both industry and academia over the past decade.
Polymer-Clay Nanocomposites presents the first comprehensive overview of the state of the art of these materials since they were first reported a decade ago. Covering both the theory and practical applications, this volume in the 'Wiley Series in Polymer Science' covers the key aspects of these important materials including:

• Polymer-clay intercalates
• The preparation and general properties of special practical and commercial significance (including strength, stiffness, toughness, permeability, fire retardation and chemical stability)
• The elucidation of the structural and rheological factors influencing performance and processing properties

The first symposium on Access in Nanoporous Materials was held in Lansing, Michigan on June 7-9, 1995. The five years that have passed since that initial meeting have brought remarkable advances in all aspects of this growing family of materials. In particular, impressive progress has been achieved in the area of novel self-assembled mesoporous materials, their synthesis, characterization and applications. The supramolecular self-assembly of various inorganic and organic species into ordered mesostructures became a powerful method for synthesis of mesoporous molecular sieves of tailored framework composition, pore structure, pore size and desired surface functionality for advanced applications in such areas as separation, adsorption, catalysis, environmental cleanup and nanotechnology.

In addition to mesostructured metal oxide molecular sieves prepared through supramolecular assembly pathways, clays, carbon molecular sieves, porous polymers, sol-gel and imprinted materials, as well as self-assembled organic and other zeolite-like materials, have captured the attention of materials researchers around the globe.

The contents of the current volume present a sampling of more than 150 oral and poster papers delivered at the Symposium on Access in Nanoporous Materials II held in Banff, Alberta on May 25-30, 2000. About 70% of the papers are devoted to the synthesis of siliceous mesoporous molecular sieves, their modification, characterization and applications, which represent the current research trend in nanoporous materials. The remaining contributions provide some indications on the future developments in the area of non-siliceous molecular sieves and related materials. This book reflects the current trends and advances in this area, which will certainly attract the attention of materials chemists in the 21st century.