
Dark blue nano tungsten oxide for thermal insulation film can be prepared by a mild H2 reduction method using a common type ammonium paratungstate or a regular type ammonium paratungstate as a raw material in a multi-tube furnace. The experimental results show that the particle size distribution of the blue tungsten oxide powder produced by the regular type ammonium paratungstate is better than that of common type ammonium paratungstate. Specifically, the ammonium paratungstate of common crystal form has an uneven…