Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843-3122, USA.
Mary Kay O'Connor Process Safety Center, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843-3122, USA.
Sci Rep. 2019 Jan 17;9(1):163. doi: 10.1038/s41598-018-36352-w.
Janus colloidal surfactants with opposing wettabilities are receiving attention for their practical application in industry. Combining the advantages of molecular surfactants and particle-stabilized Pickering emulsions, Janus colloidal surfactants generate remarkably stable emulsions. Here we report a straightforward and cost-efficient strategy to develop Janus nanoplate surfactants (JNPS) from an aluminosilicate nanoclay, halloysite, by stepwise surface modification, including an innovative selective surface modification step. Such colloidal surfactants are found to be able to stabilize Pickering emulsions of different oil/water systems. The microstructural characterization of solidified polystyrene emulsions indicates that the emulsion interface is evenly covered by JNPS. The phase behaviors of water/oil emulsion generated by these novel platelet surfactants were also investigated. Furthermore, we demonstrate the application of JNPS for enhanced oil recovery with a microfluidic flooding test, showing a dramatic increase of oil recovery ratio. This research provides important insights for the design and synthesis of two-dimensional Janus colloidal surfactants, which could be utilized in biomedical, food and mining industries, especially for circumstances where high salinity and high temperature are involved.
具有相反润湿性的 Janus 胶态表面活性剂因其在工业中的实际应用而受到关注。Janus 胶态表面活性剂结合了分子表面活性剂和颗粒稳定的 Pickering 乳液的优点，可产生非常稳定的乳液。在这里，我们报告了一种从层状硅酸铝纳米粘土（埃洛石）出发，通过逐步表面改性（包括创新性的选择性表面改性步骤）开发 Janus 纳米板表面活性剂（JNPS）的简单且经济高效的策略。发现这些胶体表面活性剂能够稳定不同油/水体系的 Pickering 乳液。固化聚苯乙烯乳液的微观结构表征表明，JNPS 均匀地覆盖在乳液界面上。还研究了这些新型板状表面活性剂生成的水/油乳液的相行为。此外，我们通过微流体驱替测试展示了 JNPS 在提高采收率方面的应用，表明采收率有了显著提高。这项研究为二维 Janus 胶态表面活性剂的设计和合成提供了重要的见解，可用于生物医学、食品和采矿等行业，特别是在涉及高盐度和高温的情况下。
