刷状高分子作为水凝胶合成的纳米构建基块《Chemistry of Materials》
Brush Polymers as Nanoscale Building Blocks for Hydrogel Synthesis
刷状高分子作为水凝胶合成的纳米构建基块
摘要
高支链官能度（f）材料作为水凝胶的构建块受到了极大的关注，因为它们形成丰富网络连接的能力产生了机械坚固的凝胶，可以潜在地耐受拓扑缺陷的负面影响。在此，我们报道了使用刷状聚合物合成水凝胶，并研究了f和聚合物拓扑结构对所得水凝胶力学性能的影响。我们的研究表明，聚合物刷的高f和延伸构象（归因于刷聚合物的纳米级形状）使它们能够表现出较高的凝胶刚度，并且可以有效地最小化拓扑缺陷的影响，在低得多的交联浓度下诱导凝胶化，与用更柔韧的聚合物制成的凝胶相比，显示出抑制的溶胀。此外，由于刷状聚合物在溶液中采用离散的纳米颗粒状形态，因此在沿着刷表面的不同点处裁剪交联基团的位置允许产生不同的拓扑连接性（例如，侧对侧和端对端），从而进一步控制交联网络的最终机械性能。因此，刷状聚合物是具有高度可调的机械和物理性能的水凝胶以及研究凝胶网络拓扑结构影响的结构-性能关系的有前途的构建基块。
Brush Polymers as Nanoscale Building Blocks for Hydrogel Synthesis
Fei Jia, Jake Song, Joshua M. Kubiak, Michika Onoda, Peter J. Santos, Koki Sano, Niels Holten-Andersen, Ke Zhang, and Robert J. Macfarlane*
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
Chem. Mater. 2021, 33, 14, 5748–5756
Publication Date: July 7, 2021
https://doi.org/10.1021/acs.chemmater.1c01585
Abstract
High branch functionality (f) materials have garnersed significant attention as building blocks for hydrogels as their ability to form abundant network connections yields mechanically robust gels that can potentially tolerate the negative effects of topological defects. Herein, we report the synthesis of hydrogels using brush polymers and investigate the influence of both f and polymer topology on the mechanical properties of resulting hydrogels. Our study suggests that both the high f and the extended conformation of polymer brushes that are attributed to the nanoscale shape of the brush polymers enable them to exhibit elevated gel stiffness and can effectively minimize the effects of topological defects, induce gelation at much lower cross-link concentrations, and display restrained swelling compared with gels made with more flexible polymers. In addition, because the brush polymers adopt discrete nanoparticle-like morphologies in solution, tailoring the location of the cross-linking groups at different points along the brush surface allows for different topological connectivities (e.g., side-to-side and end-to-end) to be generated, further controlling the resulting mechanical properties of the cross-linked networks. Brush polymers are therefore promising building blocks for hydrogels with highly tunable mechanical and physical properties and for the investigation of structure–property relationships affected by the gel network topology.
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