Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, China.
Langmuir. 2012 Jun 26;28(25):9275-81. doi: 10.1021/la300856h. Epub 2012 Jun 12.
A series of novel and stable water in oil (W/O) gel-emulsions was created by utilizing a new cholesteryl derivative, a low-molecular mass gelator (LMMGs), as a stabilizer. In the emulsions, n-heptane, n-octane, n-nonane, n-decane, tertiary butyl methacrylate (t-BMA), methyl methacrylate (MMA), or styrene can be used as a continuous phase, water as a dispersed phase, and the stabilizer in the continuous phase is only 2% (w/v). Importantly, the gel-emulsions could be prepared by simple agitation of the mixtures at room temperature, while heating, cooling, and addition of a cosolvent or other additional component are unnecessary. SEM and optical microscopy studies revealed the foam-like structures of the gel-emulsions. Rheological measurements demonstrated that the gel-emulsions are mechanically stable and exhibit typical viscoelastic properties. Surprisingly, the storage modulus, G', and the yield stress of the gel-emulsions with the alkanes as continuous phase decrease along with increasing the volume ratio of the dispersed phase, water, a property different from those of conventional gel-emulsions reported in the literature. From the viewpoint of application, the gel-emulsions as prepared are superior to others due to their simplicity in preparation, less amount of stabilizer needed, and the nonionic nature of the stabilizer, which must benefit practical applications. Furthermore, porous polymer monoliths could be prepared by polymerizing gel-emulsions with organic monomers as a continuous phase.
利用一种新型的胆甾醇衍生物低分子质量凝胶剂（LMMG）作为稳定剂，制备了一系列新型的、稳定的水包油（W/O）凝胶乳液。在乳液中，可以使用正庚烷、正辛烷、正壬烷、正癸烷、叔丁基甲基丙烯酸酯（t-BMA）、甲基丙烯酸甲酯（MMA）或苯乙烯作为连续相，水作为分散相，连续相中的稳定剂仅为 2%（w/v）。重要的是，凝胶乳液可以通过简单地在室温下搅拌混合物来制备，而无需加热、冷却以及添加助溶剂或其他添加剂。SEM 和光学显微镜研究表明，凝胶乳液具有泡沫状结构。流变学测量表明，凝胶乳液具有机械稳定性，并表现出典型的粘弹性。令人惊讶的是，与文献中报道的常规凝胶乳液不同，以烷烃作为连续相的凝胶乳液的储能模量 G'和屈服应力随着分散相水的体积比的增加而降低。从应用的角度来看，由于制备凝胶乳液的方法简单、所需稳定剂的量少以及稳定剂的非离子特性，凝胶乳液优于其他乳液，这必将有益于实际应用。此外，还可以通过聚合以有机单体为连续相的凝胶乳液来制备多孔聚合物整体材料。
