纳米二氧化硅在稻秸上的形态分布及制备工艺

为了实现农作物稻秸的多层分级利用,采用扫描电子显微镜和X-射线能谱分析仪分析硅在稻秸单元表面的存在形式和分布形态,并进一步利用稻秸制备成微纳米二氧化硅,探讨热解温度(575、675、775℃)和热解时间(2、4h)对二氧化硅得率和粒径的影响。研究表明,硅主要以二氧化硅的形式存在于稻秸表面的颗粒物区,质量分数达12.8%。热机械处理可以减小硅的粒径。在相同的热解温度下,热解时间从2h增加到4h,二氧化硅颗粒粒径逐渐增大,并且使纳米二氧化硅得率保持在8%以上。。在相同的热解时间下,热解温度上升使得二氧化硅粒径变大。球磨处理可以改善二氧化硅颗粒的团聚现象,并且使粒径从18.94μm下降到6μm以下,处于小于100nm的比例增多。研究结果为以稻秸为原料制备纳米二氧化硅提供参考。

Preparation and morphology properties of nano-silicon dioxide from rice straw

The utilization of rice straw can protect the environment and contribute to sustainable development.The distribution and morphology of silicon dioxide from rice straw was investigated with SEM-EDXA,and the nano-silicon dioxide was prepared from rice straw with pyrolysis processing.The results showed that,the silicon was distributed in granular zone of the surface of rice straw in the form of silicon dioxide,and the content was 12.8%.After thermomechanical refining,the silicon dioxide content was remained above 8%,and the dimension of silicon dioxide in the surface of fiber decreased.The dimension of silicon dioxide increased with increasing the pyrolysis time from 2 to 4 h,as while as increasing pyrolysis temperature from 575 to 775℃.After ball milling processing,the granule dimension of silicon dioxide was reduced from 18.94 to 6 μm.Furthermore,the proportion of granule dimension under 100 nm was increased.The processing parameters with pyrolysis temperature of 575℃,time of 2h and ball milling time of 10 min were suggested for nano silicon dioxide production.