A METHOD OF PREPARATION OF A NOVEL SOL FOR DEPOSITION OF ELECTROCHROMIC TUNGSTEN OXIDE THIN FILMS

摘要

A method of preparation of a novel sol for deposition of electrochromic tungsten oxide thin films by dissolving sodium tungstate in water free from organic and inorganic contaminants under stirring in the ratio of 0.5-1.0 gm of sodium tungstate : 40-120 ml of water at ambient temperature, treating the solution so obtained with mineral acid of concentration in the range of 3N-6N to obtain a precipitate, separating the precipitate from the mother liquor by filtration, washing the precipitate with water free from organic and inorganic contaminants till complete removal of metal cation of the tungstate and anion of the acid, •4 dissolving the washed precipitate in a mixture of 20-30% aqueous solution of Q hydrogen peroxide with glacial acetic acid in a ratio in the range of H2O2 O :H2COOH = 3:1, 1:3 and intermediates (v/v) under stirring, drying the resultant solution at a temperature in the range of 40°-60°C to obtain a solid mass, dissolving the solid mass so obtained in alcohol in a ratio in the range of 0.2-0.65 gm of solid mass : 10-20 ml of alcohol at a temperature in the range of 40-60°C under stirring and filtering the solution to obtain a novel sol.