摘要
为了研究气相法白炭黑的脱酸机理及工艺,对不同比表面积的未脱酸样品进行热重分析和测定pH,得出了室温至400℃范围内经流化床处理30min后气相法纳米白炭黑表面水含量与氯化氢含量间的关系。结果表明:未脱酸白炭黑中吸附水含量远大于吸附氯化氢含量。室温至250℃范围内,脱附掉的水与氯化氢成一定比例,250℃时氯化氢和物理吸附水基本完全脱附掉,且开始脱附化学吸附水。总之,氯化氢和大部分水是以物理吸附的形式吸附在白炭黑表面,较易脱附;250～400℃白炭黑的pH有微小变化,是由于温度不同,白炭黑纳米粒子表面结构不同所导致。
For studying the deacidification mechanism and technics of fumed silica, thermogravimetric analysis was applied to different specific surface area samples without deacidification and their pH values were determinated. It has acquired the content relationship between H2O and HCl on nano-sized fumed silica after treated 30 min in fluidized bed at certain temperature from room-temperature to 400 ℃. Results showed that the adsorption content of H2O was far larger than HCl on samples which have not been deacidified. HCl and physical adsorption H2O were almost completely desorbed at 250 ℃, then chemical adsorption H2O was started to desorbe. In general, HCl and most H2O adsorbed on nano-sized fumed silica were in the form of physical adsorption and were easily to be desorbed. At 250 ℃ to 400 ℃ ,little change of pH was detected due to the differences of surface structure of silica nano oarticles at certain temperature.
出处
《无机盐工业》
CAS
北大核心
2009年第4期35-37,共3页
Inorganic Chemicals Industry
关键词
白炭黑
吸附
脱酸
silica
adsorption
deacidification
