基于聚乙二醇(PEG)胶束模板法的SiO2气凝胶微球制备及性能分析
Preparation and property analysis of SiO2 aerogel microspheres by polyethylene glycol(PEG)micelle template method
高雷 1李超 1赵惠瑩 1吴明华 2王懿佳3
作者信息
- 1. 浙江理工大学纺织科学与工程学院(国际丝绸学院),杭州 310018
- 2. 浙江理工大学先进纺织材料与制备技术教育部重点实验室,杭州 310018;浙江理工大学生态染整技术教育部工程研究中心,杭州 310018;浙江理工大学绿色低碳染整技术浙江省工程研究中心,杭州 310018
- 3. 浙江理工大学先进纺织材料与制备技术教育部重点实验室,杭州 310018;浙江理工大学生态染整技术教育部工程研究中心,杭州 310018;浙江理工大学绿色低碳染整技术浙江省工程研究中心,杭州 310018;浙江理工大学桐乡研究院,浙江嘉兴 314500
- 折叠
摘要
为提高二氧化硅(SiO2)气凝胶微球的形貌规整度和疏水性,以甲基三甲氧基硅烷(MTMS)为前驱体,聚乙二醇(PEG)为软模板,水和乙醇为溶剂,氨水为催化剂和PEG亲疏水调节剂,采用碱催化法合成纳米SiO2溶胶分散液,经熟化、烘干和煅烧得到疏水SiO2气凝胶微球.探究PEG分子量和用量、氨水用量、MTMS用量和醇水体积比对微球形貌和导热系数的影响,优化制备工艺;采用扫描电子显微镜、热常数分析仪、比表面积及孔径分析仪以及视频水接触角测量仪等对微球的性能进行分析.结果表明:PEG可在醇水溶液中形成胶束,增溶MTMS,使MTMS的水解、缩合在胶束中进行,防止微球黏连.当PEG分子量为2000 Da,PEG用量为5.0 g,氨水用量为4.5 mL,MTMS用量为5.0 mL,醇水体积比为7∶3时,所制备的SiO2气凝胶微球形貌最佳,平均粒径约为1 μm,相互黏连较少,比表面积达432.817 m2/g,孔体积为0.281 cm3/g,平均孔径为2.5 nm,水接触角为137.0°±0.81°,导热系数为0.0380 W/(m·K).该研究可为疏水性SiO2气凝胶微球的制备提供一定的技术参考.
Abstract
To improve the morphology regularity and hydrophobicity of silicon dioxide(SiO2)aerogel microspheres,a nano-SiO2 sol dispersion was synthesized by alkali catalysis with methyltrimethoxysilane precursor(MTMS)as the precursor,polyethylene glycol(PEG)as the soft template,water and ethanol as the solvent,ammonia as the catalyst and the regulator for the hydrophily and hydrophobicity of PEG,and finally SiO2 aerogel microspheres were prepared by maturing,drying and calcining the SiO2 sol dispersion.The effects of weight and dosage of PEG molecular,dosage of ammonia,dosage of MTMS and alcohol-water volume ratio on morphology and thermal conductivity of microspheres were studied,and the preparation conditions were optimized;the properties of the prepared microspheres were characterized by scanning electron microscope,thermal constant analyzer,specific surface area and aperture analyzer,and video water contact angle measuring instrument.The results showed that PEG could form micelles in the mixed solution of ethanol and water,solubilize the MTMS,provide space for hydrolysis and condensation of MTMS,and prevent the adhesion of the microspheres effectively.When the molecular weight of PEG was 2000,the dosage of PEG was 5.0 g,the dosage of ammonia was 4.5 mL,the dosage of MTMS was 5.0 mL,and the ratio of alcohol to water by volume was 7∶3,regularly shaped SiO2 aerogel microspheres could be prepared with an average diameter of about 1 μm,and almost no adhesion with each other.The specific surface area of the SiO2 aerogel microspheres was as high as 432.817 m2/g,the pore volume was 0.281 cm3/g and average pore size was 2.5 nm.Meanwhile,its water contact angle was 137.0°±0.81°,and the thermal conductivity was 0.0380 W/(m·K).The study can provide technical support for the preparation of hydrophobic SiO2 aerogel microspheres.
关键词
二氧化硅/气凝胶微球/聚乙二醇/胶束/模板法Key words
silicon dioxide/aerogel microspheres/polyethylene glycol/micelle/template method引用本文复制引用
出版年
2024
NETL
NSTL
万方数据