Diffusiophoresis is the migration of a colloidal particle through a viscous fluid, caused by a gradient in concentration of some molecular solute; a long-range physical interaction between the particle and solute molecules is required. In the case of a charged particle and an ionic solute (e.g., table salt, NaCl), previous studies have predicted and experimentally verified the speed for very low salt concentrations at which the salt solution behaves ideally. The current study presents a study of diffusiophoresis at much higher salt concentrations (approaching the solubility limit). At such large salt concentrations, electrostatic interactions are almost completely screened, thus eliminating the long-range interaction required for diffusiophoresis; moreover, the high volume fraction occupied by ions makes the solution highly nonideal. Diffusiophoretic speeds were found to be measurable, albeit much smaller than for the same gradient at low salt concentrations.

扩散电泳是由于某些分子溶质的浓度梯度引起的胶体颗粒通过粘性流体的迁移。在颗粒和溶质分子之间需要长距离的物理相互作用。在带电粒子和离子溶质（例如食盐，NaCl）的情况下，先前的研究已经预测并通过实验验证了盐溶液在理想状态下的极低盐浓度下的速度。当前的研究提出了在高得多的盐浓度下（接近溶解度极限）的扩散电泳的研究。在如此高的盐浓度下，几乎完全屏蔽了静电相互作用，从而消除了扩散电泳所需的长距离相互作用。此外，离子占据的高体积分数使溶液非常不理想。