Osmotic and diffusio-osmotic flow generation at high solute concentration. I. Mechanical approaches

Abstract

In this paper, we explore various forms of osmotic transport in the regime of high solute concentration. We consider both the osmosis across membranes and diffusio-osmosis at solid interfaces, driven by solute concentration gradients. We follow a mechanical point of view of osmotic transport, which allows us to gain much insight into the local mechanical balance underlying osmosis. We demonstrate in particular how the general expression of the osmotic pressure for mixtures, as obtained classically from the thermodynamic framework, emerges from the mechanical balance controlling non-equilibrium transport under solute gradients. Expressions for the rejection coefficient of osmosis and the diffusio-osmotic mobilities are accordingly obtained. These results generalize existing ones in the dilute solute regime to mixtures with arbitrary concentrations.

Osmotic and diffusio-osmotic flow generation at high solute concentration. II. Molecular dynamics simulations

“…The time integration appearing in Eqs. (14) and (16) suffers from significant noise, and we therefore take an average over a very large time-series sample to compute the time-correlation functions. We accordingly adopt the same strategy as in Refs.…”

“…The force unbalance in the thin layer is the driving force of the diffusio-osmotic flow. As shown in the first paper of the series, 16 the fluid velocity is linearly proportional to the chemical potential gradient, according to…”

Diffusiophoresis in nonadsorbing polymer solutions: The Asakura-Oosawa model and stratification in drying films

“…The radius R is comparable to the radius of gyration of the polymer. This is a very simple model, and we believe that this paper can also serve as a pedagogical introduction to diffusiophoresis, identifying the molecular origins of the phenomena and highlighting the importance of solvent backflow [39,41,[46][47][48].…”

What Controls Thermo-osmosis? Molecular Simulations Show the Critical Role of Interfacial Hydrodynamics

“…Thermophoretic phenomena, referring to the influence of temperature gradients on the flux of colloidal particles, were firstly studied for numerous applications such as optothermal DNA trapping or diseaserelated protein aggregates identification [1][2][3][4][5][6][7][8], and this interest for thermophoresis fostered work on its theoretical description [9][10][11][12][13]. On the other hand, at variance with what has been done for electro-osmosis [14][15][16][17][18][19][20][21][22] and diffusio-osmosis [23][24][25][26], very limited theoretical work has been done so far on thermo-osmosis at solid-liquid interfaces.…”