Preparation of poly(ethylene-co-acrylic acid)/copper(I) oxide composite through melt-mixing and its near infrared absorption by sulfuration

Reducing of copper (1) oxide (Cu2O) particles was attempted to prepare an organic/inorganic nanocomposite during melt mixing of poly(ethylene-co-acrylic acid) (EAA) through cracking of the particles by shear stress in the molten polymer and ablation of Cu2O by carboxylic acid groups. The method in this study, however, was not effective for the reducing of micron-ordered particle to nano- or submicron-ordered particle. The copper components in the composite were sulfurized, and then two types of copper sulfide particles, i.e., nano-sized CuS and micron-sized CuxS (1.86 < x < 1.96), were formed. The sulfurized sample film exhibited strong ultraviolet and near-infrared absorptions, while visible ray of the wavelength around 600 nm can be relatively well passed through, thus it was sufficiently transparent in daylight. Owing to the optical absorption, an excellent heat-ray shielding property was observed, which indicates that this material can be applied for a solar ray blocking material. This property is chiefly responsible for CuS nanoparticles.