标题： 基于表面化学的微通道中通过扩散渗析和扩散渗透实现聚苯乙烯颗粒的连续分离 显示英文标题

标题： Surface chemistry-based continuous separation of polystyrene particles in a microchannel via diffusiophoresis and diffusioosmosis

摘要： 胶体粒子的分离在许多领域中非常重要，如化学、医学和化学工程。 然而，基于其表面物理化学性质分离粒子仍然具有挑战性。 扩散泳动和扩散渗流已被用于根据粒子尺寸和ζ电位连续分离胶体。 在这里，我们证明，在电解质流中，扩散泳动和扩散渗流能够分离具有相似尺寸和ζ电位但羧基表面浓度不同的羧酸盐聚苯乙烯粒子。 使用一个双接点微流控装置，通过低浓度和高浓度电解质流进料，以创建稳定状态的盐浓度梯度。 当流体沿通道混合时，粒子会暴露于不同盐度的环境中，其动力学行为受到其ζ电位对局部盐浓度敏感性的影响。 通常，对于羧酸盐聚苯乙烯粒子，通过电泳测量的ζ电位大小会随着盐浓度的增加而减小。 然而，表面电导效应取决于羧基的表面浓度，可能导致ζ电位对盐的敏感性相反。 因此，在选定的盐条件下，低浓度流中具有相似尺寸和ζ电位的聚苯乙烯胶体，但羧基表面浓度不同，当它们对盐的ζ电位敏感性相反时，可以在连续流动过程中实现分离。 这种机制在跨学科领域具有潜在应用，可用于仅通过影响其ζ电位敏感性的表面物理化学性质区分的胶体的连续分离，例如粗糙度、渗透性、异质性和化学组成。 显示英文摘要

摘要： The separation of colloidal particles is of great importance in many fields, such as chemistry, medicine, and chemical engineering. However, separating particles based on their surface physico-chemical properties remains challenging. Diffusiophoresis and diffusioosmosis have been used for the continuous separation of colloids based on particle size and zeta potential. Here, we demonstrate that diffusiophoresis and diffusioosmosis in electrolyte streams enable the separation of carboxylate polystyrene particles with similar sizes and zeta potentials but distinct surface concentrations of carboxyl groups. A double junction microfluidic device, fed with low and high electrolyte concentration streams, was used to create steady-state salt concentration gradients. As the streams mix along the channel, the particles are exposed to environments with varying salinity levels, and their dynamics are influenced by the sensitivity of their zeta potential to the local salt concentration. Typically, for carboxylate polystyrene particles, the magnitude of the electrophoretically measured zeta potential decreases with increasing salt concentrations. However, surface conductance effects, which depend on the surface concentration of the carboxyl groups, may lead to an opposite sensitivity of the zeta potential to salt. Therefore, under selected salt conditions, similarly sized polystyrene colloids with comparable zeta potentials in the low concentration stream, but different surface concentrations of carboxyl groups, can be separated in a continuous flow process when they exhibit opposite zeta potential sensitivities to salt. This mechanism has discipline-spanning potential for the continuous separation of colloids distinguished solely by surface physico-chemical properties that influence their zeta potential sensitivities, like roughness, permeability, heterogeneity, and chemical composition.