Changing the relation between micro- and mesoporosity in porous glasses: The effect of different factors
Changing the relation between micro- and mesoporosity in porous glasses: The effect of different factors
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DOI：
10.1016/j.micromeso.2014.02.002
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发表时间：
2014-05-15
影响因子：
5.2
通讯作者：
Antropova, T. V.
中科院分区：
文献类型：
--
作者：
Kreisberg, V. A.;Antropova, T. V.
采用先进的经典氮平衡吸附-脱附方法和新的扩散动力学质谱诊断方法，研究了碱硼硅酸盐玻璃溶出过程中微孔与中孔之间的关系。揭示了不同因素，如化学组成、酸处理和碱处理条件对多孔玻璃中微孔和介孔亚结构的形貌和孔特性的变化的影响。多孔玻璃的特征在于中孔（最多4个模式）和微孔（最多3个模式）的多模式尺寸分布。中孔的形状不是纯粹的圆柱形;存在圆锥形和球间孔的贡献。随着中孔比表面积的减小和二次氧化硅球径的增大，介孔体积减小。多孔玻璃中的微孔通常是二次二氧化硅中的球间接触区域，其直径为N-2分子的1-2倍。引入氧化铅允许获得具有最高比表面积、最大孔隙体积和最小孔隙直径的多孔玻璃。在玻璃基质中引入磷和氟允许产生具有最小孔隙率、中孔表面积、“孔隙体积”和具有最大中孔尺寸的多孔玻璃。当盐酸浓度从1 M增加到3 M，酸浸时间从3 h增加到9 h时，中孔比表面积减小，孔径增大。碱的作用导致中孔的单峰孔径分布，中孔体积显著增加，微孔体积显著减小。此时，由于通道壁的溶解而产生的新微孔不会产生。(C)2014爱思唯尔公司All rights reserved.
The relation between micro- and mesoporosity in the porous glasses produced by leaching of two-phase alkali borosilicate glasses was studied by use of advanced classical nitrogen equilibrium adsorption-desorption methods and new kinetic method of diffusion diagnostics with mass spectral recording. The effect of different factors, such as chemical composition, conditions of acid and alkaline treatments on the change of morphology and pore characteristics of the micro- and mesoporous substructures in the porous glasses was revealed. The porous glasses are characterized by the polymodal size distribution of mesopores (up to 4 modes) and micropores (up to 3 modes). The shape of mesopores is not purely cylindrical; there is a contribution of conical and interglobular pores. The micropore volume decreases with the decrease of the mesopore specific surface area and increasing the globule diameters of secondary silica. The micropores in the porous glasses are generally the regions of interglobular contacts in secondary silica with 1-2 times the diameter of N-2 molecules. The introducing lead oxide allows obtaining the porous glasses with the highest specific surface area, maximum micropore volume, and minimum micropore diameter. The introduction of phosphorus and fluorine in the glass matrix allows producing the porous glasses with the minimal porosity, mesopore surface area, micropore volume 'and with the maximal size of mesopores. When increasing the leaching concentration of hydrochloric acid from 1 to 3 M and acid leaching time from 3 to 9 h, the mesopore specific surface area decreases and the mesopore diameters increase. The effect of alkali leads to the monomodal pore size distribution of mesopores, significant increase in the mesopore volume, and significant reduction in the micropore volume. At this, the new micropores due to the dissolution of channel walls do not create. (C) 2014 Elsevier Inc. All rights reserved.