纳米孔超级绝热材料硅气凝胶制备与改性

Preparation and Modification of Nanoporous Super Thermal Insulator Material:Silica Aerogels

纳米孔超级绝热材料概念于 2 0世纪 90年代提出 ,已成为国际保温材料领域的研究热点 .纳米超级绝热材料的气孔尺寸小于空气平均分子自由程 (≤ 70nm)且具有很低的体积密度 ,材料在常温和设定的温度下有比空气更低的绝热系数 .随着气凝胶绝热材料研究的不断深入 ,除常规的超临界制备方法外 ,非临界干燥方法也被用于硅气凝胶的制备 .在保持材料原有的热学性能的前提下 。

The concept of super thermal insulation material originates from the nineties of the 20 th century.When the pore size of super thermal insulation material is less than the average free path of air molecule(≤70 nm) with a minimal volume density,the adiabatic coefficient of super thermal insulation material lower than that of air is achieved at normal or given temperature.With the development of super thermal insulation material,non_supercritical technique is also applied in drying silica_based aerogels besides common supercritical drying conditions.Under the premise of keeping the thermal property,the study on nanoporous thermal insulation material is unceasingly developing toward practical and engineering.