Rational Framework for Particle-containing Coacervates

凝聚体是相反电荷的聚合物的络合物，由于静电力的作用，它们从盐溶液中分离成两个液体相。它们用于涂料、粘合剂、药品和个人护理产品。这项研究将创造出新型凝聚体，其中一个带电成分是固体纳米颗粒。这项工作将通过建立现有的知识来创造新的凝聚体，探索颗粒大小和刚性如何影响两个液体相的形成，并研究颗粒表面电荷排列所起的作用。绘制这些新材料相图的实验将得到分析、识别聚合物在颗粒表面的吸附和聚合物构型的实验以及测量整体力学行为的实验的补充。最终，研究人员计划确定使用大类颗粒配制凝聚体的设计规则。作为这项工作的一部分，将为STEM领域中代表性不足的女性和其他学生提供研究机会。该奖项侧重于对聚合物粒子凝聚体的系统研究。这项工作的三个具体目标是：1)利用附着了聚合物的粒子(毛茸茸的粒子)来创建聚合物粒子凝聚体，以建立对聚合物-聚合物凝聚系统的当前理解；2)研究粒子的硬度和尺寸如何影响凝聚体的形成和性质；以及3)通过专注于静电片状粒子来研究电荷聚集对凝聚体形成的作用。这三个目标解耦了粒子性质影响凝聚体形成的假设机制，从而为使用广泛的粒子类别的凝聚体配方提供了设计规则。通过将具有毛茸茸的颗粒的凝聚体形成与线性聚阳离子和聚阴离子链的类似体系进行比较，Aim 1保留了经典凝聚体的分子相互作用，并引入了固体颗粒作为空间填充实体，其长度尺度可能因其相互作用的范围而变得重要。AIMS 2和AIMS 3依次探讨了粒子刚性、正负电荷配准中的潜在失配以及电荷聚集引入的分子尺度限制的影响。该计划利用了主要研究人员之间的协同作用：Perry(凝聚专家)和Santore(聚电解质吸附和胶体相行为专家)。马萨诸塞州大学的实验将得到UIUC合作者Sing的计算支持，他们的计算涉及聚合物-固体相互作用和相行为。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Coacervates are complexes of oppositely charged polymers that have separated into two liquid phases from a salt solution due to electrostatic forces. They are used in coatings, adhesives, pharmaceuticals, and personal care products. This research will create novel coacervates in which one of the charged components is a solid nanoparticle. The work will create new coacervates by building on existing knowledge, explore how particle size and rigidity affect the formation of the two liquid phases, and examine the role that the arrangement of charges on the particle surface plays. Experiments to map the phase diagrams for these new materials will be complemented by analysis, experiments to identify the adsorption of polymers on the particle surfaces and the polymer configurations, and experiments to measure the bulk mechanical behavior. Ultimately, the researchers plan to identify design rules for the formulation of coacervates using a broad class of particles. Research opportunities for women and other students who are under-represented in STEM fields will be provided as part of this work.This award is focused on a systematic study of polymer-particle coacervates. Three specific aims for the work are: 1) create polymer-particle coacervates employing particles with polymers attached (brushy particles) to build upon the current understanding of polymer-polymer coacervate systems, 2) examine how particle rigidity and size impact coacervate formation and properties, and 3) examine the role of charge clustering on coacervate formation by focusing on electrostatically patchy particles. The three aims decouple the hypothesized mechanisms by which particle properties affect coacervate formation, thus providing design rules for the formulation of coacervates using broad classes of particles. By comparing coacervate formation with brushy particles to the analogous system of linear polycation and polyanion chains, Aim 1 preserves the molecular interactions of a classical coacervate and introduces solid particles as space filling entities whose length scales may be important through their range of interactions. Aims 2 and 3 sequentially probe the impact of molecular scale constraints introduced by particle rigidity, potential mismatch in registration of positive and negative charge, and charge clustering. The program exploits the synergy between the principle investigators: Perry (coacervate expert) and Santore (expert on polyelectrolyte adsorption and colloidal phase behavior). The experiments at UMass will be supported by computations by collaborator Sing at UIUC whose calculations address both the polymer-solid interactions and the phase behavior.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.