TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The ratio of the tungsten hexachloride to the alcohol is 1.5-3 mM. The alcohol is ethanol, methanol, isopropanol and/or propanol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The calcining occurs at a temperature of 300-400 degrees C for 0.1-1 hour. The sol is applied to the substrate by ultrasonic spraying, where the ultrasonic spraying comprises entraining the sol in a gas comprising at least one of nitrogen, argon and/or helium. Preferred Components: The templating agent is triblock copolymer which is poly(ethylene oxide)20-b-poly(propylene oxide)70-b-poly(ethylene)20. The ratio of the tungsten hexachloride to the organic templating agent is 1:4, preferably 1:9. The substrate is at least one of glass material, membrane, or filter. The film has optical modulation of 100%. The film is bleached or colored. The film is translucent. The particle size of a nanocrystallite is 5-20 nm in the film. EXAMPLE - 1 g Pluronic P123 (RTM: Poly(ethyleneoxide)-b-poly(propylene oxide)-b-poly(ethylene) was dissolved in 10 ml anhydrous ethanol. The sol was completed by adding 0.595 g tungsten hexachloride to the triblock copolymer/ethanol solution, followed by 12 hours of stirring to produce sol. The stable sols was transferred to a syringe and delivered to the ultrasonic spray nozzle at a flow rate of 0.25 ml/minute. The ultrasonic spray system operated at a frequency of 120kHz. The spray nozzle had a 0.230 in diameter conical tip and 0.015 in diameter orifice that was fitted with the impact system for gas-driven spray delivery. The atomized mist was entrained in a stream of nitrogen whose flow-rate was fixed at 6.9 slm using an electronic mass flow controller. This aerosol was directed onto fluorinated tin oxide coated glass positioned 5 cm below the nozzle under ambient conditions. Before deposition, all substrates were cleaned with an isopropanol-soaked clean-room wipe, blown dry with nitrogen, and then placed in an oxygen plasma (800 mtorr, 155 W) for 5 minutes. The final step was calcination, where sample was heated in air to remove residual solvent and the polymer template while completing the oxidation and crystallization of the tungsten oxide. The resulting product was placed directly onto a hot plate set at maintained at 350 degrees C. After 1 hour on the hot plate the sample was removed and allowed to naturally cool down to room temperature.