Banerjee Anirudha, Squires Todd M
Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106-5080, USA.
Sci Adv. 2019 Aug 16;5(8):eaax1893. doi: 10.1126/sciadv.aax1893. eCollection 2019 Aug.
Structures and particles that slowly release solute into solution can attract or repel other particles in suspension via diffusiophoresis, a process we termed "soluto-inertial (SI) interactions." These SI interactions involve "beacons" that establish and sustain nonequilibrium solute fluxes over long durations. Here, we demonstrate the versatility of the SI concept and introduce distinct strategies to manipulate solute gradients and, hence, suspension behavior using beacons with different physicochemical properties. First, we demonstrate on-demand particle migration using beacons that can be actuated with a trigger. We then show the synergy between multiple, distinct beacons that modify solute fluxes in a way that allows directed, yet selective, colloidal migration to specific target sites. Moreover, this multibeacon harmony enhances migration velocities, and delays the equilibration of the SI effect. The different SI techniques highlighted here suggest previously unidentified possibilities for sorting and separating colloidal mixtures, targeting particle delivery, and enhancing rates of suspension flocculation.
能够缓慢向溶液中释放溶质的结构和颗粒，可通过扩散泳作用吸引或排斥悬浮液中的其他颗粒，我们将这一过程称为“溶质-惯性（SI）相互作用”。这些SI相互作用涉及“信标”，它们能在长时间内建立并维持非平衡溶质通量。在此，我们展示了SI概念的通用性，并介绍了不同的策略，以利用具有不同物理化学性质的信标来操纵溶质梯度，进而控制悬浮行为。首先，我们利用可通过触发启动的信标展示了按需粒子迁移。然后，我们展示了多个不同信标之间的协同作用，这些信标以一种允许定向但选择性的胶体迁移到特定目标位点的方式改变溶质通量。此外，这种多信标协同作用提高了迁移速度，并延迟了SI效应的平衡。此处强调的不同SI技术为胶体混合物的分选和分离、靶向粒子递送以及提高悬浮液絮凝速率提供了此前未被发现的可能性。
