Characterisation of bio-silica synthesised from cogon grass (Imperata cylindrica)
Characterisation of bio-silica synthesised from cogon grass (Imperata cylindrica)
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DOI：
10.1016/j.powtec.2014.01.018
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发表时间：
2014-03-01
影响因子：
5.2
通讯作者：
Abdullah, E. C.
中科院分区：
文献类型：
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作者：
Kow, Kien-Woh;Yusoff, Rozita;Abdullah, E. C.
无定形二氧化硅由于材料的高表面积和火山灰性质而具有许多应用。本工作以白茅为原料，通过在650℃下燃烧合成无定形二氧化硅。通过将热重分析（TGA）数据拟合到Flynn-Wall-Ozawa模型确定了燃烧的动力学参数，其中相应的活化能和频率因子分别为202.5+/-5.1kJmol(-1)和（7.9+/-6.7） x 10(15) s(-1)。能量色散 X 射线 (EDX) 分析表明白茅的二氧化硅含量相对较低 (2.9 wt.%)。此外，X射线衍射（XRD）数据表明，所得二氧化硅的纯度和无定形度受杂草中钾含量的显着影响。然而，酸浸过程去除了杂质，并将二氧化硅的纯度从 31.4 wt.% 提高到 83.4 wt.%。通过小角X射线散射(SAXS)测定的二氧化硅颗粒的一次粒径(a)和质量分形维数(D)分别为19.8nm和2.4。 (C) 2014 Elsevier B.V. 保留所有权利。
Amorphous silica has many applications due to the material's high surface area and pozzolanic properties. In this work, amorphous silica was synthesised from cogon grass (Imperata cylindrica) by combustion at 650 degrees C. Kinetic parameters of the combustion were determined by fitting thermogravimetric analysis (TGA) data to the Flynn-Wall-Ozawa model, where the corresponding activation energy and frequency factor are 202.5 +/- 5.1 kJ mol(-1) and (7.9 +/- 6.7) x 10(15) s(-1). Energy-dispersive X-ray (EDX) analysis revealed that cogon grass has a relatively low silica content (2.9 wt.%). In addition, X-ray diffraction (XRD) data showed that the purity and amorphicity of silica obtained are significantly affected by the potassium content in the weed. However, the process of acid leaching removed the impurities and increased the purity of silica from 31.4 wt.% to 83.4 wt.%. The primary particle size (a) and the mass fractal dimension (D) of silica particles determined by small-angle X-ray scattering (SAXS) were 19.8 nm and 2.4, respectively. (C) 2014 Elsevier B.V. All rights reserved.