Preparation and Characterization of Sodium Silicate-based Silica Aerogels by Ambient Pressure Drying and their Energy Saving Applications

• Main Authors: WANG, CHUNG-YU, 王崇佑
• Other Authors: HSIEH, TAR-HWA
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/538zvv

碩士 === 國立高雄科技大學 === 化學工程與材料工程系 === 107 === In this study, silica aerogels (SAs) were prepared by sol-gel process at ambient pressure drying, where the sodium silicate behaved as a precursor of silicate source and the hexamethyldisilazane used as a hydrophobic modifier. The containing SA silicate cement (SC) and UV curable epoxy resin (UEP) composite coatings were fabricated, in which the SC and the UEP used as the inorganic and organic substrate, respectively. The process parameters of solvent exchange, stirring period and drying temperature of SA were further discussed. Results showed that, the SA prepared at 1500 rpm for 5hrs and dried at 60 °C has a higher contact angle (130.2°), porosity (86.59%) and lower heat transfer coefficient (0.06543 W/mK). In addition, containing 5 wt% SA SC coating, the energy saving rate can reach to 66.26% and the maximum operate temperature can achieve 300°C for insulation applications. As for containing 5 wt% SA UEP coating, the average absorbance is 0.2108 at 300-380 nm, the average transmittance is 79.15% at 380-780 nm and the average absorbance is 0.0749 at 780-2500 nm can be observed. The containing 5 wt% SA SC and UEP coatings can significantly apply for steel pipe/tank insulation and architectural glass energy saving.