生物质制备无定形SiO_2及其表面改性

Synthesis of amorphous silica from biomass and its surface modification

将稻壳灰与碳酸钠溶液反应,采用沉淀法制备SiO2,滤饼用聚乙二醇6000(PEG6000)进行表面改性。结果表明:在反应温度100℃、料液比为15g:300mL、碳酸钠浓度18wt.%、反应时间3.5h时SiO2的产率达95.2%,XRD表征为高度无定形结构。滤饼在100mL水中分散,当改性温度80℃、改性时间1.5h、PEG6000的相对添加量为15%时,改性后的SiO2的DBP吸着率达2.78mL/g,相对于未改性的DBP吸着率2.08mL/g增加0.7mL/g,FT-IR谱图表明,采用PEG6000改性后的SiO2表面得到明显改善。

Amorphous silica was prepared from rice husk ash and sodium carbonate solution by precipitation method. Then the filter cake was prepared with surface modification by polyethylene glycol 6000（PEG6000）. The result showed that the dissolution rate of silica reached 95.2 %at the temperature 100℃, solid-liquid ratio 15g ：300mL, concentration of Na2 CO3 solution 18wt and reaction time 3.5hours. And the X-ray diffraction pattern of silica powders shown a typical amorphous structure. The cake was dispersed in 100mL water, when the modification temperature 80 ℃, the reaction time 1.5h, modified PEG 6000 relative content was 15 % ,the prepared modified silica DBP sorption rate of 2.78mL/g,compared with the unmodified DBP sorption rate of 2.08mL/g was increased 0.70mL/g,the prepared products were improved significantly. The structure and properties of silica were characterized by FF-IR showed that the silica modified via PEG6000 was improved obviously.