Ding Peng, Liu Wei, Guo Xuhong, Cohen Stuart Martien A, Wang Junyou
State-Key Laboratory of Chemical Engineering, and Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, 130 Meilong Road, 200237, Shanghai, People's Republic of China.
Soft Matter. 2021 Jan 28;17(4):887-892. doi: 10.1039/d0sm01715a. Epub 2020 Nov 25.
Polyelectrolyte (PE) nanogels which combine features of nanogels and polyelectrolytes have attracted significant attention as outstanding nano-carriers. However, and crucially, any large-scale application of PE nanogels can only materialize when an efficient production method is available. We recently developed such a robust approach, namely Electrostatic Assembly Directed Polymerization (EADP), in which ionic monomers are polymerized together with cross-linker in the presence of a polyion-neutral diblock copolymer as template. Although EADP achieves efficient and scalable preparation of diverse PE nanogels, the essential factors for the optimal and controlled synthesis of nanogels have remained elusive. In this article, we investigate systematically the effects of pH, salt concentration, and cross-linker fractions on the formation and properties of a PDMAEMA nanogel prepared with PAA-b-PEO as the template. We find that the electrostatic interaction between the building blocks is crucial to obtain assembly-controlled polymerization, and we establish preferred pH, salt concentration and cross-linker fractions. The obtained PDMAEMA nanogel exhibits dual-responses to pH and salt, which allow manipulation of the positive charges of the nanogels for selective loading and controlled release of anionic substances; we demonstrate this with an anionic dye. The study presented here fully addresses the process parameters of EADP regarding optimal and controlled preparation of PE nanogels, which should allow exploration of their potential vis-a-vis a variety of applications.
兼具纳米凝胶和聚电解质特性的聚电解质（PE）纳米凝胶作为出色的纳米载体已引起广泛关注。然而，至关重要的是，只有当有高效的生产方法时，PE纳米凝胶的任何大规模应用才能实现。我们最近开发了一种强大的方法，即静电组装定向聚合（EADP），其中离子单体在聚离子中性二嵌段共聚物作为模板的存在下与交联剂一起聚合。尽管EADP实现了多种PE纳米凝胶的高效且可扩展的制备，但纳米凝胶最佳和可控合成的关键因素仍不明确。在本文中，我们系统地研究了pH值、盐浓度和交联剂比例对以PAA-b-PEO为模板制备的PDMAEMA纳米凝胶的形成和性质的影响。我们发现构建单元之间的静电相互作用对于获得组装控制的聚合至关重要，并且我们确定了优选的pH值、盐浓度和交联剂比例。所获得的PDMAEMA纳米凝胶对pH值和盐具有双重响应，这使得可以操纵纳米凝胶的正电荷以选择性负载和控制释放阴离子物质；我们用一种阴离子染料证明了这一点。本文提出的研究全面阐述了EADP在PE纳米凝胶最佳和可控制备方面的工艺参数，这应该有助于探索它们在各种应用中的潜力。
