Department of Chemistry, National Central University, Chung-Li 32054, Taiwan, ROC.
Department of Chemistry, National Central University, Chung-Li 32054, Taiwan, ROC.
J Hazard Mater. 2014 Aug 15;278:539-50. doi: 10.1016/j.jhazmat.2014.06.016. Epub 2014 Jun 20.
Periodic mesoporous organosilicas (PMOs) with benzene bridging groups in the silica wall were functionalized with a tunable content of phosphonic acid groups. These bifunctional materials were synthesized by co-condensation of two different organosilane precursors, that is, 1,4-bis(triethoxysilyl)benzene (BTEB) and sodium 3-(trihydroxysilyl)propyl methyl phosphate (SPMP), under acidic conditions using nonionic surfactant Brij-S10 as template. The materials exhibited well-ordered mesostructures and were characterized by X-ray diffraction, nitrogen sorption, TEM, TGA, FTIR, and solid-state NMR measurements. The materials thus obtained were employed as adsorbents to remove different types of dyes, for example, cationic dyes methylene blue and phenosafranine, anionic orange II, and amphoteric rhodamine B, from aqueous solutions. The materials exhibited a remarkably high adsorption capacity than activated carbon due to their ordered mesostructures, a large number of phosphonic acid groups, and high surface areas. The adsorption was mainly governed by electrostatic interaction, but also involved π-π stacking interaction as well as hydrogen bonding. The adsorption kinetics can be better fitted by the pseudo-second order model. The adsorption process was controlled by the mechanisms of external mass transfer and intraparticle diffusion. The materials retained more than 97% dye removal efficiency after use for five consecutive cycles.
具有苯桥联基团的周期性介孔有机硅（PMO）在二氧化硅壁中功能化有可调含量的膦酸基团。这些双功能材料是通过两种不同的有机硅烷前体的共缩合合成的，即 1,4-双（三乙氧基硅基）苯（BTEB）和 3-（三羟基硅基）丙基甲基膦酸钠（SPMP），在酸性条件下使用非离子表面活性剂 Brij-S10 作为模板。该材料具有有序的介孔结构，并通过 X 射线衍射、氮气吸附、TEM、TGA、FTIR 和固态 NMR 测量进行了表征。所得到的材料被用作吸附剂，用于从水溶液中去除不同类型的染料，例如阳离子染料亚甲蓝和酚藏花红、阴离子染料橙 II 和两性染料罗丹明 B。与活性炭相比，由于其有序的介孔结构、大量的膦酸基团和高的表面积，该材料表现出了极高的吸附容量。吸附主要受静电相互作用控制，但也涉及π-π堆积相互作用以及氢键。吸附动力学可以更好地拟合伪二阶模型。吸附过程由外部传质和颗粒内扩散机制控制。该材料在使用五次连续循环后仍保持超过 97%的染料去除效率。
