摘要
本实验以正硅酸乙酯(TEOS)为硅源,甲基三乙氧基硅烷(MTES)为共前驱体,超纯水(H2O)为反应剂,无水乙醇(EtOH)为溶剂,盐酸(HCl)和氨水(NH 3·H 2O)为催化剂,采用酸碱两步催化二次改性常压干燥制备了超疏水性SiO2气凝胶。利用N2吸附-脱附测试、傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)和接触角测定等手段对气凝胶的结构和性能进行表征,系统研究了水的用量、无水乙醇的用量以及溶胶的pH值对气凝胶性能的影响。结果表明:当TEOS、MTES、EtOH、H2O物质的量比为1∶0.3∶14∶6时制备的气凝胶性能最好,其热导率为0.0212 W/(m·K),比表面积为920 m^2/g,孔径主要分布在2~20 nm,密度为0.109 g/cm^3,孔隙率为95.05%,接触角为158.7°。
In this dissertation,silica aerogels with super-hydrophobic were prepared via acid-base two-step modification,followed by atmospheric pressure drying process.They were synthesized with tetraethoxysilane(TEOS)as the silicon source,methyltriethoxysilane(MTES)as the precursor,ultrapure water(H 2O)as the reactant,ethanol(EtOH)as solvents,hydrochloric acid(HCl)and ammonia(NH3·H2O)as catalysts.N2 adsorption-desorption test,FTIR,XRD,SEM and contact angle tests were used to characterize silica aerogels.The effect of the molar ratio of EtOH/TEOS,the molar ratio of H2O/TEOS,the pH of the sol were systematically studied for aerogel performance influences.The results indicated that the aerogels prepared with n(TEOS)∶n(MTES)∶n(EtOH)∶n(H2O)=1∶0.3∶14∶6 had the best properties.The thermal conductivity,specific surface area,average pore size,density,porosity,contact angle were 0.0212 W/(m·K),920 m^2/g,2-20 nm,0.109 g/cm 3,95.05%,158.7°,respectively.
作者
闫秋会
夏卫东
罗杰任
霍鑫
YAN Qiuhui;XIA Weidong;LUO Jieren;HUO Xin(School of Building Services Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China;Institute of Urban Planning and Municipal Engineering,Xi’an Polytechnic University,Xi’an 710048,China;Shaanxi Huaxia New Energy Technology Co.,Ltd,Xi’an 710016,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2020年第12期12173-12177,共5页
Materials Reports
基金
陕西省重点研发计划项目(2018SF-355)
动力工程多相流国家重点实验室开放基金
碑林区科技计划项目(GX1804)。
关键词
SIO
2气凝胶
常压干燥
超疏水性
纳米材料
脱附
silica aerogel
ambient pressure drying
superhydrophobic
nanomaterials
desorption
