Abstract: An optical chemical sensor comprises an optical waveguide having a light transmitting substrate and a coating of an environmentally sensitive compound in a Zr/Si sol-gel glass binder on the substrate. The sensor is suitable for use in high pH environments. The environmentally sensitive compound may be a chemically sensitive dye e.g. a pH indicator dye.

Abstract: A fine metal oxide powder is prepared by a method comprising the steps of (1) preparing a hydroxide precursor of a metal oxide, (2) mixing the precursor with an inorganic compound having a melting point lower than the crystallization temperature of the metal oxide, and (3) subjecting the resulting mixture to a high temperature thermal treatment to form the fine metal oxide powder.

Abstract: The invention relates to the preparation of conductive metal oxide powders.The method according to the invention comprises the following stages: a) a colloidal aqueous solution of crystalline particles of at least one metal oxide or a composite oxide of several metals is formed, by hydrolysing a starting solution containing metal ions and an agent for complexing the metals, (b) heat treatment is carried out. Any residual salts and residual complexing agent are eliminated before or during the heat treatment (b).Application to the manufacture of antistatic coatings.