Synthesis of nano CuS and its effects on the light transmittance, thermal insulation, and mechanical properties of CuS/PVB composite film

Nano copper sulfide (CuS) is a kind of good thermal insulation nanomaterial with low visible light absorption and high infrared light blocking rate. In this study, sodium sulfide (NaS), thiourea, copper chloride dihydrate (CuCl₂·2H₂O), and copper nitrate trihydrate (Cu(NO₃)₂·3H₂O) were used as sulfur source and copper source to prepare two kinds of nano CuS by hydrothermal method, and the surface of the nano CuS was treated with alkoxysilane (KH570). And then, with polyvinyl butyral (PVB) melt blending extrusion pelleting, PVB composite film was prepared, and the light transmittance, heat insulation performance, and mechanical properties were studied. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to characterize the nano CuS, and the results showed that the nano CuS exhibited two morphologies, flake and hollow, respectively. The PVB composite film doped with hollow CuS has higher visible light transmittance and lower thermal conductivity, which are 82.7% and 0.191 W/(m·K), respectively. Meanwhile, the mechanical properties of the film are significantly improved with the rate 0.3/100 for hollow CuS/PVB.

In this study, two forms of nano CuS were used as fillers and fused with PVB to form glass intermediate films, and the light transmittance, thermal insulation, and mechanical properties of the glass intermediate film were studied.