Water-dispersible sulfopolyesters are a major class of film-forming and solution-modifying polymers, which are routinely used in applications such as inks, adhesives, coatings, and personal care products. Since these polyesters are designed to be used as waterborne dispersions, understanding their colloidal interactions in dispersions is critical for their application. By using a range of commercially available water-dispersible sulfopolyesters as a model system, we investigated the relationship between their molecular composition, colloidal interactions, and phase equilibria. We established how these polyesters undergo different molecular configurations and nanoaggregated states, depending on the nature of the liquid medium. For example, the polyesters are in a solvated molecular form in certain organic solvents, whereas they self-assemble into compact nanoaggregates in water. We found that the interactions of these nanoaggregates follow the classical DLVO theory of critical colloidal coagulation where the stability of these nanoparticles is extremely sensitive to multivalent electrolytes (i.e., C_crit ∝ z⁻⁶). By using static, dynamic, and electrophoretic light scattering, we correlate their nanoscale intermolecular and interparticle interactions with corresponding macroscale phase behavior in both organic medium and water, based on the theoretical framework of second virial coefficients. We present a model for nanoaggregate formation in water based on the critical surface charge density of these nanoparticles. Such fundamental understanding of colloidal interactions could be used to efficiently control and improve the colloidal stability and film-formation ability of these polyesters and may enable the design of novel high-performance surfactant-free waterborne dispersion systems.

中文翻译：

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回顾水分散性聚酯的胶体基础：水中聚合物纳米聚集体的相互作用和自组装†

水分散性磺基聚酯是一类主要的成膜和溶液改性聚合物，通常用于油墨，粘合剂，涂料和个人护理产品等应用中。由于这些聚酯被设计用作水性分散体，因此了解它们在分散体中的胶体相互作用对其应用至关重要。通过使用一系列可商购的水分散性磺基聚酯作为模型系统，我们研究了它们的分子组成，胶体相互作用和相平衡之间的关系。我们根据液体介质的性质，确定了这些聚酯如何经历不同的分子构型和纳米聚集态。例如，聚酯在某些有机溶剂中呈溶剂化分子形式，而它们在水中自组装成紧密的纳米聚集体。我们发现这些纳米聚集体的相互作用遵循临界胶体凝聚的经典DLVO理论，其中这些纳米颗粒的稳定性对多价电解质极为敏感（即，Ç_暴α Ž ^-6）。通过使用静态，动态和电泳光散射，基于第二病毒系数的理论框架，我们将它们的纳米级分子间和粒子间相互作用与相应的宏观相在有机介质和水中的行为相关联。我们基于这些纳米颗粒的临界表面电荷密度，提出了一种在水中形成纳米聚集体的模型。对胶体相互作用的这种基本理解可以用于有效控制和改善这些聚酯的胶体稳定性和成膜能力，并且可以设计新颖的高性能无表面活性剂的水性分散体系。