Despite tremendous progress in macromolecular self-assembly, the influence of topology and hydrolysis on hierarchical self-assembly has been scarcely revealed. This study aims at the design of toothbrush-like copolymers with linear and cyclic backbones to reveal multi-tunable properties, and the introduction of pH/oxidation-responsive and hydrolyzable Y junctions endows the copolymers with unique hydrolysis-induced topological and morphological transformations. The cyclization of the polymer backbone can lead to distinct bulk and solution properties such as chain relaxation, solution viscosity and self-assembly, revealing the crucial role of cyclic architecture. Upon pH and oxidation stimuli, at least eight kinds of distinct nanostructures involving spheres, vesicles, disks and sea urchins are achieved by self-assembly. Hydrolysis-induced (co)assembly dependent on topology, pH and hydrolysis time offers programmable formation of a diversity of nanostructures. Both toothbrushes can self-assemble into unilamellar vesicles, while the vesicles bearing cyclic toothbrushes are readily converted into double-lamellar vesicles upon heating, sonication and short-time pH stimulus. Our research can provide new insight into topology-related formation and transition processes of polymer nanoparticles. The success of this study paves the way for macromolecular engineering towards promising shape-dependent properties and applications.

中文翻译：

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含多反应性Y键和线性或环状骨架的pH值可裂解牙刷状共聚物的合成和性能

尽管在高分子自组装方面取得了巨大进展，但几乎没有揭示拓扑和水解对分级自组装的影响。这项研究的目的是设计具有线性和环状骨架的牙刷状共聚物，以揭示其多重可调性，并且引入pH /氧化响应和可水解的Y键可赋予共聚物独特的水解诱导的拓扑和形态转化。聚合物主链的环化可导致独特的体积和溶液性质，例如链松弛，溶液粘度和自组装，从而揭示了环状结构的关键作用。在pH和氧化刺激下，通过自组装获得了至少八种不同的涉及球，囊泡，圆盘和海胆的纳米结构。水解诱导的（共）组装取决于拓扑结构，pH和水解时间，可提供多种纳米结构的可编程形成。两种牙刷都可以自组装成单层囊泡，而带有环状牙刷的囊泡在加热，超声和短期pH刺激下很容易转变为双层囊泡。我们的研究可以为与拓扑相关的聚合物纳米粒子的形成和过渡过程提供新的见解。这项研究的成功为高分子工程向有希望的形状依赖性特性和应用铺平了道路。而带有循环牙刷的囊泡在加热，超声和短期pH刺激下很容易转变为双层囊泡。我们的研究可以为与拓扑相关的聚合物纳米粒子的形成和过渡过程提供新的见解。这项研究的成功为高分子工程向有希望的形状依赖性特性和应用铺平了道路。而带有循环牙刷的囊泡在加热，超声和短期pH刺激下很容易转变为双层囊泡。我们的研究可以为与拓扑相关的聚合物纳米粒子的形成和过渡过程提供新的见解。这项研究的成功为高分子工程向有希望的形状依赖性特性和应用铺平了道路。