Making Nano-porous SiO2 Insulation Through Filter-Pressing of Foamed Slurry
Nano-porous SiO2 insulation material was made from foamed aqueous slurry ofnano-silica powder by filter-pressing.The foamed aqueous slurry mainly consists of hydrophobic SiO2 nano-particles,xonotlite whiskers and glass fiber.The latter two will enhance strength of the insulation material.Rheological properties of the foamed slurry with varying solid mass concentration were studied.The effect of forming pressure on the density and pore size distribution of the nano-porous silica material was investigated.It was found that the foamed slurry with solid concentration less than 17% behaves pseudoplastic as decreasing its apparent viscosity with increasing of shear rate during rheological testing.Homogeneous foamed slurry can be obtained when solid concentration in it is below 7%.Such slurry should be dewatered into solid concentration being of 10-15% before filter-pressing.Rigorously stirring of the concentrated slurry is required before pouring it into a mould,which helps to reduce the viscosity of the slurry and fill mould uniformly.During pressing the loading speed should be strictly controlled in order to reaching designed pore size distribution in SiO2 insulation material.The SiO2 insulation material with apparent density about 0.45g/cm3 and pore size mainly ranging from 10 to 50nm was obtained.
Nano porous SiO2 insulation Foamed slurry
SHI Xing OUYANG Shixi CHEN Yufeng LI Maoqiang ZHANG Shichao WU Wei WANG Guanghai SUN Haoran
High Performance Ceramics and Fine Processing Lab,China Building Materials Academy,Beijing,China
国际会议
The Seventh China International Conference on High-Performance Ceramics (第七届先进陶瓷国际研讨会(CICC-7))
厦门
英文
319-322
2011-11-04（万方平台首次上网日期，不代表论文的发表时间）