Marbach Sophie, Kavokine Nikita, Bocquet Lydéric
Laboratoire de Physique de l'Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France.
J Chem Phys. 2020 Feb 7;152(5):054704. doi: 10.1063/1.5138987.
To overcome the traditional paradigm of filtration, where separation is essentially performed upon steric sieving principles, we explore the concept of dynamic osmosis through active membranes. A partially permeable membrane presents a time-tuneable feature that changes the effective pore interaction with the solute and thus actively changes permeability with time. In general, we find that slow flickering frequencies effectively decrease the osmotic pressure and large flickering frequencies do not change it. In the presence of an asymmetric membrane, we find a resonant frequency where pumping of the solute is performed and can be analyzed in terms of ratchet transport. We discuss and highlight the properties of this resonant osmotic transport. Furthermore, we show that dynamic osmosis allows us to pump the solute at the nanoscale using less energy than reverse osmosis. This opens new possibilities to build advanced filtration devices and design artificial ionic machinery.
为了克服基于空间筛分原理进行分离的传统过滤模式，我们探索了通过活性膜实现动态渗透的概念。部分渗透膜具有随时间可调的特性，这会改变与溶质的有效孔隙相互作用，从而使渗透率随时间主动变化。一般来说，我们发现缓慢的闪烁频率能有效降低渗透压，而大的闪烁频率则不会改变渗透压。在存在不对称膜的情况下，我们发现了一个共振频率，在该频率下溶质会被泵送，并且可以根据棘轮输运进行分析。我们讨论并强调了这种共振渗透输运的特性。此外，我们表明动态渗透使我们能够在纳米尺度上泵送溶质，且所需能量比反渗透少。这为构建先进的过滤装置和设计人工离子机械开辟了新的可能性。
