It appears that most organizations are at the exploratory or development stage, with little evidence to date of large-scale commercial activity. However, the conference demonstrated that we have passed the stage of asking whether the technology is fact or fiction, as it is now clear that there is a commercial reality behind the publicity.
The papers presented tended to split into those that addressed the fundamental issues of mechanisms, synthesis and characterization, and those further down the development chain, which addressed specific performance improvements and practical applications.
Production via sol-gel techniques featured prominently as the method of choice for synthesizing inorganic-organic hybrid composites. Radiation curing offers several advantages as the preferred method for further reaction, as thermal curing requires extended heating at elevated temperatures, which would not be commercially viable on a volume production scale. Ambient pressure plasma treatments are still at a very early stage of development.
The main performance properties that the new technology is designed to deliver are scratch and abrasion resistance, UV absorption, anti-corrosion and anti-bacterial/pollution properties. Other performance targets are improved gas barrier properties, flame retardency, tannin stain blocking and easy-to-clean properties. Sometimes the technology delivers multiple benefits at the same time.
As new technology tends to come with an increased price tag, commercial pressures will help drive the selection of markets where the performance improvements will have commensurate added value. Certainly the Hygiene market must be a good candidate for exploitation, given the widespread problems of hospital-acquired infections. We have probably reached the point at which marketing involvement is now required to focus the scientific work on the most profitable objectives.
The papers covered a variety of raw materials that show a change in properties as their size is reduced to the nano scale, e.g., clay (typically montmorillonite), silica, TiO2, alumina, CeO2. The changes in properties arise from the increase in specific surface area and increase in reactivity. These inorganic components have been reacted with various organic binder polymers, for example, acrylics, epoxies, polyester resins and polyvinylidene fluoride. Test results were presented for nanocomposites and hybrid systems applied over various substrates, including wood, aluminium, glass and polycarbonate.
Various sophisticated techniques were described that have been used to analyze the morphology of composites at the nano scale, including SEM, TEM, and AFM.
The papers demonstrated that a large number of variables are involved in optimizing a particular composition, although some of the fundamental principles will apply across the field of the technology. Thus, solutions to problems in one area may help solve problems in a related area. To develop a full understanding of the mechanisms involved, the need for an interdisciplinary approach is clear.
The general consensus was that it would be appropriate to hold the conference again in two years, due to the high level of research resources being devoted to the area and the need to communicate and debate new developments as they are produced. Potential delegates are invited to send any suggestions as to content or format to the conference organizers. One area of concern in the future will no doubt be the regulatory environment.
The conference proceedings represent an excellent summary of the "state of the art" in this important area, comprising the papers authored by leading researchers from universities, suppliers and fabricators. Copies may be obtained by contacting Janet Saraty, conference administrator, at www.pra.org.uk. The price is £150 (PRA Members £120).
