论文标题
推进胶体被中尺度分离所包围的条件
Conditions for the propulsion of a colloid surrounded by a mesoscale phase separation
论文作者
论文摘要
我们研究了活性各向同性胶体的二维模型，该模型的推进与浴缸的溶质颗粒之间的相互作用有关。胶体在其附近催化化学反应，从而产生溶质颗粒的局部相分离。溶质颗粒的密度波动导致胶体扩散增强。使用数值模拟，我们彻底研究了发生活动的条件，并建立了胶体活性作为模型参数的函数的状态图。我们使用生成的数据来揭示可观察到的关键，该关键可控制活性的存在和强度：反应区域的填充部分。值得注意的是，我们最终表明，推进也发生在三维几何形状中，这证实了该机制对实验应用的兴趣。
We study a two-dimensional model of an active isotropic colloid whose propulsion is linked to the interactions between solute particles of the bath. The colloid catalyzes a chemical reaction in its vicinity, that yields a local phase separation of solute particles. The density fluctuations of solute particles result in the enhanced diffusion of the colloid. Using numerical simulations, we thoroughly investigate the conditions under which activity occurs, and we establish a state diagram for the activity of the colloid as a function of the parameters of the model. We use the generated data to unravel a key observable that controls the existence and the intensity of activity: the filling fraction of the reaction area. Remarkably, we finally show that propulsion also occurs in three-dimensional geometries, which confirms the interest of this mechanism for experimental applications.
