Synthesis, Characterization, and Infrared Blocking Efficiency of Polyvinyl Alcohol Composites Filled with Cadmium Sulfide and Zinc Sulfide NPs

Abstract

This investigation explores the efficiency of composite coatings, leveraging polyvinyl alcohol (PVA) matrices embedded with zinc sulfide (ZnS) and cadmium sulfide (CdS) nanoparticles, for their infrared (IR) radiation blocking potential. Such coatings are strategically synthesized via a sol-gel method, targeting applications that demand IR attenuation, including but not limited to, construction, architectural fenestrations, vehicular glazing, and thermal insulation domains. In these composites, meticulous integration of ZnS and CdS nanoparticles within the PVA framework was demonstrated to significantly bolster their IR reflective or absorptive properties, consequently curtailing heat transference. It has been observed that nanoparticle concentration and coating thickness serve as critical factors, directly correlating with the IR-blocking proficiency-enhanced concentrations and augmented thicknesses invariably yield superior performance metrics. The surface morphology, assessed through Atomic Force Microscopy (AFM), revealed a positive correlation between nanoparticle concentration and surface roughness, paralleling an increase in particle size. This observation is corroborated by scanning electron microscopy, attesting to the uniform nanoparticle distribution. Fourier-transform infrared spectroscopy (FTIR) analysis identified novel peaks at approximately 1280 and 1700 cm -1 , indicative of a chemical interaction between ZnS nanoparticles and the PVA matrix, as evidenced by the presence of reactive functional groups on the ZnS nanoparticle surface. Thermogravimetric analysis (TGA) imparted insights into the thermal stability of the specimens, with CdS composites exhibiting a weight loss of 98.73%, in stark contrast to the 91.04% manifested by the ZnS counterparts. The disparity is attributed to the higher boiling point of CdS (1750℃) vis-à -vis ZnS (1700℃), underscoring the material's intrinsic thermal resilience. The findings from this research underscore the potential of PVA-ZnS and PVA-CdS coatings as viable candidates for IR-blocking applications, positing an innovative solution to thermal management challenges in various sectors.