
Nano tungsten trioxide has photochromic properties so that it may be applied for producing thermal insulating glass, which plays a role of heat insulation. And therefore, it saves cooling fee, prevents furniture from fading, and protects people from sunburn. When it comes to photochromism, what you may have known is the early appearance of photochromic materials. The appearance of those photochromic materials: In 1867, it was first discovered that yellow tetracene compounds faded under the influence of air and light,…