Yu Heng, Wang Qin, Zhao Yongliang, Wang Haitao
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200433, China.
Shanghai Dilato Materials Co., Ltd., Shanghai 200433, China.
ACS Appl Mater Interfaces. 2020 Mar 25;12(12):14607-14619. doi: 10.1021/acsami.0c01273. Epub 2020 Mar 13.
Functional porous materials show extensive applications in the environment, biology, aerospace, and so on. In this work, the generation of silica foams and functionalization of pore surface were simultaneously realized through an interfacial sol-gel reaction within high internal phase emulsion (HIPE) microreactors, where a hyperbranched polyethoxysiloxane (PEOS) was used as the sole stabilizer for the HIPEs. With various functional substances containing amino, epoxy, and carboxyl groups initially dissolved in the aqueous phase of HIPEs, these functional groups could be grafted onto the pore surface in the process of forming silica foams. Amino-functionalized silica foam showed fast adsorption of sunset yellow, and the adsorption capacity could reach as high as 1213.13 mg/g. Sodium polyacrylate-modified silica foam exhibited good adsorption capacity of cationic dyes and metal ions, e.g., 280.11 mg/g to methylene and 226.24 mg/g to Cu(II). Epoxy-functionalized silica foam particles were confirmed with a pronounced activity at the oil/water interface due to their Janus-like surface, which could be used as Pickering stabilizer. This HIPE-based synthesis strategy for silica foams shows promising future in adsorption, emulsion stabilization, and compatibilization.
功能性多孔材料在环境、生物、航空航天等领域有着广泛的应用。在本工作中，通过高内相乳液（HIPE）微反应器内的界面溶胶-凝胶反应，同时实现了二氧化硅泡沫的生成和孔表面的功能化，其中超支化聚乙氧基硅氧烷（PEOS）被用作HIPEs的唯一稳定剂。由于各种含有氨基、环氧基和羧基的功能物质最初溶解在HIPEs的水相中，这些官能团可以在形成二氧化硅泡沫的过程中接枝到孔表面。氨基功能化的二氧化硅泡沫对日落黄表现出快速吸附，吸附容量可达1213.13mg/g。聚丙烯酸钠改性的二氧化硅泡沫对阳离子染料和金属离子表现出良好的吸附能力，例如对亚甲基蓝为280.11mg/g，对Cu(II)为226.24mg/g。环氧功能化的二氧化硅泡沫颗粒由于其类Janus表面而在油/水界面具有显著的活性，可作为Pickering稳定剂。这种基于HIPE的二氧化硅泡沫合成策略在吸附、乳液稳定和增容方面显示出广阔的前景。
