凹凸棒粘土磷酸活化前后的分形特征

The Surface Fractal Properties of Attapu lgite pre-and post-phosphoric Acid Activation

凹凸棒粘土是一种多孔的粘土材料,对气相和液相中的污染物均有很好的净化效果.采用N2吸附法研究了不同浓度磷酸活化对凹凸棒石粘土的比表面积、孔结构以及表面分性特征的影响.结果表明,凹凸棒粘土磷酸改性后比表面积和分形维数明显增大,具有明显的中孔分布.

The attapulgite is a porous clay material, and can adsorb varied pollutant in gas phase and liquid phase. In order to understand the performance of attapulgite on the gas adsorption, the surface area and pore distribution of attapulgite and three activated attapulgites were studied by using their nitrogen adsorption isotherms. Their fractal dimensions were also calculated by a method based on FHH（Frenkel-Halsey-Hill） model. The results indi- cate that the fractal dimensions of the attapulgite is slightly more than 2, however, the phosphoric acid-activated attapulgites are 2.6 or so. Furthennore, the phosphoric activated-attapulgites showed obvious meso-porous distribution and larger surface area.