HNTs/SiO_2复合气凝胶制备及其性能研究  

Preparation and Properties of HNTs/SiO_2 Composite Aerogels

作　　者：刘洪丽 何翔 李洪彦 杨爱武 肖然 魏宁 

机构地区：[1]天津城建大学材料科学与工程学院,天津300384 [2]天津市软土特性与环境工程重点实验室,天津300384

出　　处：《人工晶体学报》2017年第11期2277-2282,共6页Journal of Synthetic Crystals

基　　金：天津市应用基础与前沿技术研究计划重点项目(15JCZDJC37200);天津市科技支撑计划项目(16YFZCSF00500)

摘　　要：采用正硅酸乙酯(TEOS)为硅原,以硅烷改性的埃洛石纳米管(HNTs)为增强相,利用CO_2超临界干燥技术制备具有优良力学和隔热性能的HNTs/SiO_2复合气凝胶。利用傅立叶红外光谱、扫描电镜、比表面积与孔径分析仪、万能试验机和导热率测量仪等手段对HNTs改性后的表面状态、HNTs/SiO_2复合气凝胶的微观形貌、孔结构、力学和导热性能进行了测试分析。结果表明:改性后的HNTs均匀分散到二氧化硅气凝胶基体中,并与SiO_2纳米颗粒实现良好的结合,HNTs/SiO_2复合气凝胶呈三维网络结构,当HNTs含量为15wt%时,平均孔径为10.47 nm;随着HNTs含量的增加,复合气凝胶的力学性能不断增强,同时其导热系数也不断增大,当HNTs含量为15wt%时,HNTs/SiO_2复合气凝胶的抗压强度为0.85 MPa,导热系数为0.024 W/m K。HNTs/Si02 composite aerogels with excellent mechanical properties and thermal insulation performance were prepared via supercritical C02 drying, employing tetraethoxysilane （TEOS） as silicon source and halloysite nanotubes （ HNTs） modified by isooctyltriethoxy silane as reinforcing phase. Surface states of HNTs after modification, the morphology, pore structure, mechanical properties, and thermal conductivity of composite aerogels were investigated by FTIR, SEM, surface area and porosity analyzer, universal testing machine and thermal conductivity measurement. Our results reveal that the modified HNTs are uniformly dispersed into the silica gel matrix, and make good combinations with Si02 nanoparticles. HNTs/Si02 composite aerogels exhibit a three-dimensional network structure, when the content of HNTs is 15wt%,the average pore size of aerogels is 10. 47 nm; with the increase of HNTs content, the mechanical properties of composite aerogels are improved, and the thermal conductivity also increase continuously. When the HNTs content is 15wt% , the compressive strength of HNTs/Si02 composite aerogel is 0. 85 MPa, and the thermal conductivity is 0.024 W/mK.

关 键 词：HNTs 复合气凝胶 力学性能 导热性能 

分 类 号：O648[理学—物理化学]