SiO_(2)高效节能气凝胶隔热材料的制备及性能研究  

Study on preparation and properties of SiO_(2) high efficiency energy saving aerogel thermal insulation materials

作　　者：李月香[1] 马军霞[1] 王蒙[2] LI Yuexiang;MA Junxia;WANG Meng(School of Civil Engineering&Architecture,Hebei University of Engineering Science,Shijiazhuang 050091,China;School of Civil Engineering,Hebei University of Engineering Science,Shijiazhuang 050091,China)

机构地区：[1]河北工程技术学院土木与建筑学院,石家庄050091 [2]河北工程技术学院土木工程学院,石家庄050091

出　　处：《功能材料》2024年第7期7224-7230,共7页Journal of Functional Materials

基　　金：河北省教育厅高等学校科学技术研究项目(Z2020128);国家自然科学基金项目(52015005)。

摘　　要：以N,N-二甲基甲酰胺为干燥剂,通过常压干燥法制备了SiO_(2)气凝胶隔热材料,研究了正硅酸乙酯和水的摩尔比对SiO_(2)气凝胶形貌、物相结构、孔径分布、力学性能和导热性能的影响。结果表明,SiO_(2)气凝胶隔热材料为典型的非晶结构,具有有序的介孔孔道,随着水摩尔比的增大,气凝胶的孔道结构有序度逐渐提高,宏观形貌更加完整且致密,摩尔比n(TEOS)∶n(水)=1∶30制备出的气凝胶的多孔网格结构最为致密。随着水摩尔比的增大,SiO_(2)气凝胶的比表面积、抗压强度先增大后降低,导热系数先降低后增大。当摩尔比n(TEOS)∶n(水)=1∶30时,气凝胶比表面积最大为441 m^(2)/g,对应的孔体积为0.414 cm^(3)/g,孔径分布为3.75 nm,抗压强度最大为29.79 kPa,导热系数最低为0.022 W/(m·K),保温性能最优。以TMCS和正己烷对SiO_(2)气凝胶进行疏水改性,体积比V(TMCS)∶V(正己烷)=1∶10时,SiO_(2)气凝胶表面的接触角达到最大值139.6°,疏水性能最佳,热稳定性也得到改善。Using N,N-dimethylformamide as desiccant,SiO_(2) aerogel thermal insulation materials were prepared by atmospheric drying method.The effects of the molar ratio of tetraethyl orthosilicate and water on the morphology,phase structure,pore size distribution,mechanical properties and thermal conductivity of SiO_(2) aerogel were studied.The results showed that the SiO_(2) aerogel thermal insulation material was a typical amorphous structure with ordered mesoporous channels.With the increase of the molar ratio of water,the ordered degree of the pore structure of the aerogel gradually increased,and the macro morphology was more complete and compact.The porous grid structure of the aerogel prepared by the molar ratio of n(TEOS)∶n(water)=1∶30 was the most compact.With the increase of water mole ratio,the specific surface area and compressive strength of SiO_(2) aerogel first increased and then decreased,and the thermal conductivity first decreased and then increased.When the molar ratio n(TEOS)∶n(water)=1∶30,the maximum specific surface area of the aerogel was 441 m^(2)/g,the corresponding pore volume was 0.414 cm^(3)/g,the pore size distribution is 3.75 nm,the maximum compressive strength was 29.79 kPa,and the minimum thermal conductivity was 0.022 W/(m·K).The thermal insulation performance was optimal.SiO_(2) aerogels were hydrophobic modified with TMCS and n-hexane.When the volume ratio of n(TMCS)∶n(n-hexane)=1∶10,the contact angle of the surface of SiO_(2) aerogels reached the maximum value of 139.6°.The hydrophobic property was the best and the thermal stability was also improved.

关 键 词：SiO_(2)气凝胶 导热系数 疏水改性 热稳定性 保温性能 

分 类 号：TQ427.26[化学工程]