Polymer-mediated colloidal stability: on the transition between adsorption and depletion
Polymer-mediated colloidal stability: on the transition between adsorption and depletion
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DOI：
10.1016/j.cis.2019.102077
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发表时间：
2020-01-01
影响因子：
15.6
通讯作者：
Vis, Mark
中科院分区：
文献类型：
--
作者：
Garcia, Alvaro Gonzalez;Nagelkerke, Marjolijn M. B.;Vis, Mark
在胶体分散体中加入聚合物可调节胶体之间的相互作用。我们简要回顾了正吸附和负吸附（也称为耗竭）的影响。有效的胶体-聚合物相互作用敏感地影响胶体相行为。我们提出了一个理论框架来预测胶体-聚合物混合物的相行为，以改变胶体和聚合物之间的亲和力，导致聚合物段的正或负吸附。在某些条件下，聚合物既不被耗尽也不被吸附：聚合物浓度在胶体表面之前基本上是恒定的，我们称之为中性吸附。在此条件下，计算得到的相图显示，随着聚合物浓度的增加，出现了稳定-不稳定-再稳定的转变。类似的效应在实验中也有报道，例如作为温度的函数[Feng等人，Nat. Mat., 2015,14, 61-65]，这可能会调节聚合物-胶体的有效亲和力。了解如何实现中性吸附打开了制备高密度，但稳定的胶体-聚合物混合物的可能性。(C) 2019作者。Elsevier B.V.出版
Addition of polymers to a colloidal dispersion modulates the interactions between the colloids. We briefly review the effects of positive and negative adsorption (also termed depletion). The effective colloid-polymer interactions sensitively affect the colloidal phase behavior. We present a theoretical framework to predict the phase behavior of colloid-polymer mixtures for varying affinities between colloid and polymer, leading to either positive or negative adsorption of polymer segments. For certain conditions, polymers are neither depleted nor adsorbed: the polymer concentration is essentially constant up to the colloidal surface, a condition which we term neutral adsorption. Near this condition, the calculated phase diagrams reveal a stable-unstable-restabilisation transition with increasing polymer concentration. Similar effects have been reported experimentally, for instance as a function of temperature [Feng et al., Nat. Mat., 2015, 14, 61-65], which may modulate the effective polymer-colloid affinity. Understanding how to achieve neutral adsorption opens up the possibility of preparing highly dense, yet stable, colloid-polymer mixtures. (C) 2019 The Authors. Published by Elsevier B.V.