基于排除体积相互作用的胶体构筑基元的可规模化尺寸与形状选择性纯化

中文摘要 AI 辅助

仅由空间位阻约束产生的排除体积相互作用，在决定胶体悬浮液的结构、动力学和相行为中发挥关键作用，这对于非球形颗粒尤为重要，此时取向相关效应也变得显著。本研究采用耗竭驱动的相分离，开发了一种可规模化的尺寸选择性方法，用于纯化同时具有凹面和凸面表面积相互作用的球形与非球形胶体团簇。对尺寸范围为267至1008 nm的电荷稳定聚苯乙烯球的相图表明，混溶-不混溶转变发生在一定范围的表面活性剂浓度内，而非单一阈值。利用该转变宽度，可在单一步骤中从二元混合物中纯化尺寸比低至1.6的单一组分。当将相同方法应用于四聚体胶体团簇时，其相对于未配位球的富集倍数达15倍。重要的是，分选效率不仅取决于有效尺寸，还取决于聚集体的几何形状；例如，各向异性的弱融合团簇比球形聚集体分选效率更高，因为与未融合团簇相比，其凹面曲率更小。这些发现确立了排除体积驱动的分选作为一种实用且可规模化的途径，用于纯化用于分级组装的胶体构筑基元。

英文摘要

Excluded-volume interactions, arising solely from steric constraints, play a crucial role in determining the structure, dynamics, and phase behaviour of colloidal suspensions. This is particularly important for non-spherical particles, where orientation-dependent effects also become significant. In this study, we employ depletion-driven phase separation to develop a scalable, size-selective method for purifying spherical and non-spherical colloidal clusters that exhibit an interplay of concave and convex surface areas. Phase diagrams of charge-stabilised polystyrene spheres ranging in size from 267 to 1008 nm demonstrate that the mixing-demixing transition occurs across a range of surfactant concentrations rather than at a single threshold. Taking advantage of this transition width enables the purification of a single component from binary mixtures at size ratios as low as 1.6 in a single step. When the same approach is applied to tetrameric colloidal clusters, these are enriched fifteenfold relative to uncoordinated spheres. Importantly, the efficiency of sorting depends not only on the effective size but also on the geometry of the aggregate. For instance, anisotropic, weakly fused clusters separate more efficiently than spherical aggregates because their concave surface curvature is reduced compared to unfused clusters. These findings establish excluded-volume-driven sorting as a practical and scalable route for purifying colloidal building blocks for hierarchical assembly.

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DOI

10.1016/j.jcis.2026.141419