Department of Chemistry, Dalian University of Technology, Dalian, Liaoning 116024, PR China.
Laboratory of Biotechnology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, PR China.
J Colloid Interface Sci. 2017 Apr 15;492:73-80. doi: 10.1016/j.jcis.2016.12.069. Epub 2016 Dec 31.
A series of monodispersed microspheres with hierarchically porous structures were prepared by microfluidic devices. Phase separation of the silica sol in microdroplets was adopted to construct these structures. The effects of velocity ratios (for both the continuous and the dispersed phases), collection solvents and calcination temperatures were investigated. The diameters of the microspheres were tuned from 148μm to 940μm by adjusting the velocity ratio. Tests revealed that the surface areas and pore volumes of the microspheres can reach 495mg and 0.6068mlg, respectively. The macroporous structure can be controlled by the collection solvents, and the wettability of the microspheres is determined by the calcination temperature. A calcination temperature of 450°C leads to a hydrophilic surface property. FeO nanoparticles were added to the silica sol to form magnetic microspheres, and the porous structure was not affected. This kind of hybrid microsphere adsorbs 3.29 times its own weight in toluene. These spheres can adsorb oil on water surfaces, and then be removed from the water with an external magnetic field. The microspheres can be recovered and reused more than 10 times.
采用微流控装置制备了具有分级多孔结构的一系列单分散微球。采用硅溶胶在微滴中的相分离来构建这些结构。考察了流速比（连续相和分散相）、收集溶剂和煅烧温度的影响。通过调整流速比，微球的直径可从 148μm 调至 940μm。测试表明，微球的比表面积和孔体积分别可达 495mg 和 0.6068mlg。大孔结构可通过收集溶剂进行控制，微球的润湿性由煅烧温度决定。煅烧温度为 450°C 时，表面具有亲水性。将 FeO 纳米颗粒添加到硅溶胶中形成磁性微球，不会影响多孔结构。这种混合微球在甲苯中的吸附量可达其自身重量的 3.29 倍。这些球体可以吸附水面上的油，然后用外部磁场将其从水中去除。微球可以回收并重复使用 10 多次。
