TiO_(2)遮光剂对气凝胶涂料绝热性能的影响

Impact of TiO_(2) on the Thermal Insulation Performance of Aerogel Thermal Insulation Coatings

针对SiO_(2)气凝胶在高温下热导率高致使其在高温应用受到限制的情况,采用掺杂纳米TiO_(2)遮光剂制备气凝胶复合绝热涂料,改善其绝热性能,研究纳米TiO_(2)遮光剂的微观形貌、红外透过率、质量光谱衰减系数对涂料绝热性能的影响。结果表明:40nm锐钛矿型TiO_(2)和25nm、60nm金红石型TiO_(2)红外光谱透过率相对较低、相应地质量光谱衰减系数较高,对热辐射的阻碍能力相对较强。气凝胶分别与60nm、25nm金红石型TiO_(2)质量比为1:1、与40nm锐钛矿型TiO_(2)质量比为1:1.5时,涂料都有较低的红外透过率;加入TiO_(2)遮光剂后,绝热涂层表面温度和导热系数均降低,说明TiO_(2)作为遮光剂可有效地屏蔽红外波,阻隔热传递,提高涂料的绝热性能。

Doped nano-TiO_(2) sunscreen is employed to prepare aerogel composite thermal insulation coating to improve its thermal insulation performance aiming at the high thermal conductivity of SiO 2 aerogel at high temperature,which limits its application at high temperature.The influence of the microscopic morphology,infrared transmittance and mass spectrum attenuation coefficient of the nano-TiO_(2) sunscreen on the thermal insulation performance of the coating is investigated.The results show that 40nm anatase TiO_(2) and 25nm,60nm rutile TiO_(2) have relatively low infrared spectral transmittance,and the highest mass spectral attenuation coefficient has relatively strong resistance to thermal radiation.When the mass ratio of aerogel to 60nm,25nm,rutile TiO_(2) is 1:1,and the mass ratio of 40nm anatase TiO_(2) is 1:1.5,the coatings have lower infrared transmittance.It is found,by examinating the thermal insulation performance and thermal conductivity of the coating,that after adding TiO_(2) sunscreen,the surface temperature and thermal conductivity of the thermal insulation coating are reduced,indicating that TiO_(2) as a sunscreen can effectively shield infrared waves,thereby,effectively block the heat transfer and improve the heat insulation performance of the coating.