Magnetically-active Pickering emulsions stabilized by hybrid inorganic/organic networks
Magnetically-active Pickering emulsions stabilized by hybrid inorganic/organic networks
复制标题
通过混合无机/有机网络稳定的磁活性皮克林乳液
DOI：
10.1039/c6sm01830k
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发表时间：
2016
期刊：
影响因子：
3.4
通讯作者：
Wooley, Karen L.
中科院分区：
文献类型：
--
作者：
Flores, Jeniree A.;Jahnke, Ashlee A.;Pavia-Sanders, Adriana;Cheng, Zhengdong;Wooley, Karen L.
磁性杂化网络(MHN)是由胺功能化的氧化铁纳米粒子(胺离子)与预组装的壳层交联型捏合型聚合物纳米结构偶联而成的复杂的无机/有机复合材料。这些材料的复杂结构是由几束相互连接的SCK共价结合到胺离子上组成的，这赋予了它们磁响应性。MHN最初的设计目的是从水中隔离复杂的碳氢化合物；然而，在机械刺激下，它们已经显示出在有机溶剂和水之间形成稳定的Pickering乳状液的非凡能力。两种乳化方法，旋涡法和探针法，已经被用来产生磁性活性的水中甲苯和水中十二烷乳状液，在MHN存在下，它们可以稳定长达两个月。详细研究了水油体积比(W ： O)和MHN浓度对乳液液滴尺寸的影响，结果表明，在所有实验条件下，W ： O=3 ： 1时，乳液的液滴尺寸最小，分散性最窄。此外，涡流法和探针法制备的乳状液中MHN的浓度分别为1mgmL−1和1.5mgmL−1，足以产生最小的液滴和最窄的分布。此外，MHN稳定的油滴具有磁性，可以在外加磁场的作用下进行操纵。
Magnetically-active hybrid networks (MHNs) are complex inorganic/organic composite materials that have been synthesized from the coupling of amine-functionalized iron oxide nanoparticles (amine-IONs) and pre-assembled shell crosslinked knedel-like (SCK) polymeric nanoconstructs. The intricate structure of these materials is composed of several inter-connected bundles of SCKs covalently bound to amine-IONs, which afford them magnetic responsivity. The MHNs were originally designed to sequester complex hydrocarbons from water; however, they have displayed a remarkable ability to form stable Pickering emulsions between organic solvents and water, upon mechanical stimulus. Two methods of emulsification, vortex and probe sonication, have been utilized to yield magnetically-active toluene-in-water and dodecane-in-water emulsions, which are stable for up to two months in the presence of the MHNs. A detailed study of the effect of the water-to-oil (W : O) volume ratio and the MHN concentration on the droplet size of the emulsions revealed that the smallest droplet size, and narrowest dispersity were obtained at a W : O = 3 : 1, for all conditions tested. Additionally, concentrations of MHNs as low as 1 mg mL−1 and 1.5 mg mL−1, for emulsions prepared via vortex and probe sonication, respectively, were sufficient to yield the smallest droplets and narrowest distributions. Furthermore, the oil droplets stabilized by the MHNs exhibited magnetic character, and could be manipulated with an external magnetic field.