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.

中文翻译：

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聚合物介导的胶体稳定性：在吸附和耗竭之间的过渡。

将聚合物添加到胶体分散体中可调节胶体之间的相互作用。我们简要回顾了正负吸附（也称为耗竭）的影响。有效的胶体-聚合物相互作用会敏感地影响胶体的相行为。我们提出了一个理论框架，以预测胶体与聚合物混合物在胶体与聚合物之间的亲和力变化时的相行为，从而导致聚合物链段的正吸附或负吸附。在某些条件下，聚合物既不会耗尽也不会被吸附：在胶体表面，聚合物的浓度基本上是恒定的，我们称这种条件为中性吸附。在此条件附近，计算出的相图显示随着聚合物浓度的增加，稳定-不稳定-再稳定化转变。实验上已经报道了类似的作用，例如，作为温度的函数[Feng等，Nat.Natl.Acad.Sci.USA，87：1877]。Mat。，2015，14，61-65]，其可以调节有效的聚合物-胶体亲和力。了解如何实现中性吸附，为制备高密度但稳定的胶体-聚合物混合物提供了可能。