标题： 基于表面化学的微通道中通过扩散渗透和扩散渗流对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，如纯化、传感和生物分析。然而，基于其表面物理或化学性质分离粒子仍然具有挑战性。本研究通过实验和理论分析表明，扩散泳动和扩散渗流能够实现对羧酸盐聚苯乙烯粒子的连续分离，这些粒子具有相似的尺寸和ζ电位，但表面羧基浓度不同。在所提出的方法中，粒子被暴露于双接点微流控装置中产生的盐浓度梯度，该装置分别输入低和高电解质浓度的流体。当粒子穿过不同盐度环境时，它们的动态受到其ζ电位对局部盐浓度敏感性的影响，而这种敏感性又受到由表面羧基引起的表面电导效应的影响。通过利用这些效应，当粒子表现出相反的ζ电位对盐的敏感性时，具有相近ζ电位但不同表面羧基浓度的胶体粒子可以以100%的效率进行分离。这种方法简单，依赖于一个易于操作且无需外部能源的装置，具有跨学科的潜力，可用于仅通过影响其ζ电位敏感性的表面特性（如粗糙度、渗透性、异质性和化学组成）来区分的胶体的连续分离。 显示英文摘要

摘要： The separation of colloidal particles is of great importance in many fields, such as purification, sensing, and bioanalysis. However, separating particles based on their surface physical or chemical properties remains challenging. This study demonstrates through experimental and theoretical analyses that diffusiophoresis and diffusioosmosis enable the continuous separation of carboxylate polystyrene particles with similar sizes and zeta potentials but distinct surface concentrations of carboxyl groups. In the proposed approach, the particles are exposed to salt concentration gradients generated in a double-junction microfluidic device, fed with low and high electrolyte concentration streams. As the particles move across environments with varying salinity levels, their dynamics are influenced by the sensitivity of their zeta potential to the local salt concentration, which in turn is affected by surface conductance effects induced by the surface carboxyl groups. By harnessing these effects, colloids with comparable zeta potentials but different surface concentrations of carboxyl groups are separated with 100% efficiency when they exhibit opposite zeta potential sensitivities to salt. This simple approach, which relies on an easy-to-operate device with no external energy source, has discipline-spanning potential for the continuous separation of colloids distinguished solely by surface properties that influence their zeta potential sensitivities, like roughness, permeability, heterogeneity, and chemical composition.