Organic-inorganic hybrids

Citation

Bean, J. (2000), "Organic-inorganic hybrids", Pigment & Resin Technology, Vol. 29 No. 3. https://doi.org/10.1108/prt.2000.12929caa.002

Organic-inorganic hybrids

Organic-inorganic hybrids

Keywords: Hybrids, Conferences

Organic-inorganic hybrids are, of course, not new. They have been the subject of many research programmes in universities and research institutes in the last two decades of the twentieth century, but with little take-up by industry. However, with the increasing demand for more "designer materials" the twenty-first century's advanced technologies will see more use made of organic-inorganic hybrid systems. Achieved by intimate chemical combination of organic with inorganic materials or plasticising an inorganic by intercalation of polymer particles, they have the advantage of being able to be produced on a nano-scale. An important international conference on these hybrid systems has now been arranged for 12-14 June at the University of Surrey, Guildford, UK. It is being organized by the PRA of Teddington, Tel: +44 (0)20 8614 4811. Fax: + 44 (0)20 8614 4812. Co-organizers are Macro Group UK, TWI, and Society of Glass Technology. Co-sponsors are the Institute of Materials and Kluwer Academic Publishers. This forum has been designed to enhance synergy between academia and industry to accelerate this exciting technology, thus opening the gateway to previously unimaginable market opportunities.

Rather than list the materials, products and their properties that will be covered at the conference, an indication of its scope can be gathered by the following synopses of a few of the 40 papers being presented.

From the University of Tokyo comes the paper "Preparation and properties of inorganic-organic fnctionally graded films". Transparent inorganic-organic functionally graded thin films of thickness less than 100nm were formed on organic substrates. The relative concentrations of organic and inorganic materials in the film varied with depth. The film is self-organised by polymer adsorption, and applicable by any conventional coating processes. Any metal alkoxides, utilised in sol-gel process, can be employed as inorganic materials source.

"Scratch-resistant coatings produced using sol-gel techniques" is the subject from Cambridge University. Two coatings with different ratios of organic/inorganic content were produced on glass and aluminium substrates, and cured over a range of times and temperatures. The hardness of the coating is shown to depend on the cure conditions and the organic content. Results of wear testing of the sol-gel coatings are compared with test samples; surface modification of the substrate by the coating is shown to change the wear mechanism of glass and to improve the scratch resistance of aluminium.

From China's Changchun Institute of Applied Chemistry there is a paper on "Preparation of nylon 6/layered silicate and mechanical model for polymer nanocomposites". Nylon 6/layered silicate nanocomposites were prepared by in situ polymerisation. Very small amounts of layered silicate in the composite can result in a large increase in tensile modulus. A three-phase mechanical model, based on Takayanagi's two-phase model, is proposed to explain the increase. When the size of the dispersed phase approaches nanoscale, both the dispersed phase and the interfacial region contribute to tensile modulus, resulting in a dramatic increase.

From Synetix PCEO, UK, comes a paper on "Organo titanates and zirconates and their utilisation in various coatings applications". Organotitanates and zirconates as a group of compounds find widespread use across the coatings industry, e.g. adhesion promoters in inks for the flexible packaging industry, thixotropic agents for colloid stabilised decorative emulsion paints and adhesion promoters/curing agents for heat and corrosion resistant paints. The compounds are liquids so offer the benefit of being easily incorporated into coating formulations. The low toxicity is an added benefit when compared to other coatings additives.

"Multifunctional nanocomposite coatings and bulk materials" is the subject of a paper from TNO-TPD, The Netherlands. Multifunctional nanocomposite coatings and bulk materials have been developed based on a combination of purely organic or hybrid organic-inorganic polymeric systems with inorganic nanoparticles, in particular anisotropic synthetic and natural clays, modified for compatibility. Separate clay platelets can be homogeneously dispersed in wet coating formulations, cured coating systems or polymeric bulk materials. Improved barrier properties, corrosion resistance and thermal stability have been introduced.