Synthesis and characterization of silica gel composite with thermal conductivity enhancers and polymer binders for adsorption desalination and cooling system

Abstract

Adsorption desalination and cooling is a promising technology that has recently been investigated. In this study, a silica gel powder composite (SGPC) with nano-copper (NC) and polyvinyl pyrrolidone (PVP) was synthesized by mechanical grinding and melt blending for the first time. It can improve the thermal conductivity of silica gel powder (SGP) and the operation efficiency of the adsorption desalination and cooling system (ADCS). By measuring the curve of temperature variation to compare the four thermal conductivity enhancers (TCE), graphite powder (GP), carbon nanotubes (CNT), nano-alumina (NA) and NC, it was found that NC had the best thermal conductivity enhancement. The microstructure, adsorption and thermal properties of the SGPC samples were systematically characterized by scanning electron microscopy (SEM), thermogravimetric analyzer (TGA) and thermal constant analyzer. The results showed that the adsorption capacity of SGPC with NC content of 0–1.6 wt% was in the range of 0.29–0.33 g−1. The thermal conductivity of SGPC with NC content of 0.8wt%, 1.2 wt%, and 1.6 wt% was found to be improved by 114%, 156% and 185% compared to the parent SGP, and the thermal conductivity was effectively enhanced. Thus, the developed adsorbent has eximious water adsorbability and thermal conductivity and has good adsorption/desorption cycle stability, which is attractive for ADCS.