摘要
由水玻璃(黑山膨润土制得)制备非晶态的纳米二氧化硅粉末。考察了乙醇浓度,电解质用量对白炭黑粒度的影响;酸化温度及酸化终点pH值对白炭黑回收率及质地的影响。并利用X射线衍射仪,红外光谱仪,扫描电子显微镜,粒度仪等对产品进行表征。研究结果表明当水玻璃的酸化温度为15℃时,产品白度下降,且回收率较低;当酸化温度为60℃时,红外分析显示SiO_2分子中Si-O键和-OH增多,结合XRD图谱分析,SiO_2分子中含有结晶水,呈结晶状,从扫描电子显微镜中可观察到SiO_2粒径很大且不均匀;当酸化温度为30℃时,产品粒径均匀,为非晶态。由此确定水玻璃制备白炭黑的最佳工艺条件为:乙醇浓度为3.4 mol/L,Na Cl用量为0.5 g,在30℃时用一定浓度的硫酸溶液中和至pH=8.5,烘干后得白炭黑。此时得到的白炭黑回收率高,粒径均匀,达到纳米级别。
Amorphous nano-silica powder is prepared by sodium silicate（ prepared by Heishan Bentonite）. The effects of concentration of ethanol,electrolyte dosage,acidification temperature and p Hvalue on nano-silica rate of recover and particle size were investigated. The product is characterized by Xray diffractometer,Infrared spectrometer,scanning electron microscope and particle size analyze. The results indicate that when the acidification temperature is 15 ℃,the whiteness of SiO2 and the rate of recover are decrease; when the acidification temperature is 60 ℃,IR analysis shows Si-O and-OH are more,combining X-ray diffractometer,crystalline water is containned in SiO2,as crystals. That can be observed from the SEM that SiO2 particle size is big and uneven; when the acidification temperature is 30℃,the particle size is uniform and SiO2 is amorphous. The optimum conditions for amorphous nano silica preparation from sodium silicate are determined as follows： the concentration of ethanol is 3. 4 mol / L,electrolyte dosage is 0. 4 g,acidification with a certain concentration of sulfuric acid solution to pH = 8. 5,SiO2 is prepared after drying. At this time,SiO2 recovery rate is high and particle size is uniform. Nano materials is prepared.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2016年第3期879-883,共5页
Bulletin of the Chinese Ceramic Society
基金
辽宁省教育厅项目(05L339)
关键词
白炭黑
非晶态二氧化硅
回收率
white carbon black
amorphous nano-silica
rate of recovery
