Yu Yadong, Kong Kangren, Mu Zhao, Zhao Yueqi, Liu Zhaoming, Tang Ruikang
Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China.
State Key Laboratory for Silicon Materials, Zhejiang University, Hangzhou, Zhejiang 310027, China.
ACS Appl Mater Interfaces. 2020 Dec 2;12(48):54212-54221. doi: 10.1021/acsami.0c18242. Epub 2020 Nov 17.
Inspired by inorganic oligomers and their polymerization, we herein develop a heterogeneous inorganic polymerization tactic that can be used to prepare a muscle-like hybrid hydrogel by inducing the polymerization of calcium phosphate oligomers (CPO) onto a polyvinyl alcohol (PVA) molecular chain network. In this heterogeneous process, the CPO units bond with PVA molecules assistance from sodium alginate (SA), and then gradually polymerize along the organic chains to form ultrafine hydroxyapatite nanolines with a diameter of ∼1 nm. Because of the well integration of organic and inorganic phases from the heterogeneous polymerization, the hierarchical structured hydrogel can exhibit ultratough mechanical properties of ∼17.84 MPa in strength and ∼8.97 kJ m in fracture energy, which exceed natural muscles and almost synthetic hydrogels. Moreover, the damaged hydrogel can be repaired readily by adding the precursors of CPO, PVA, and SA, which can induce re-polymerization. The hydrogel also exhibits muscle-like rotational motion under aqueous conditions, which can be developed into a water-driven biomimetic motor. This study indicates that inorganic polymerization can achieve a novel organic-inorganic integration rather than conventional organic-inorganic composition, and it provides a novel tactic for design and manufacture of advanced materials.
受无机低聚物及其聚合反应的启发，我们在此开发了一种非均相无机聚合策略，该策略可用于通过诱导磷酸钙低聚物（CPO）在聚乙烯醇（PVA）分子链网络上聚合来制备肌肉状杂化水凝胶。在这个非均相过程中，CPO单元在海藻酸钠（SA）的协助下与PVA分子结合，然后沿着有机链逐渐聚合形成直径约为1 nm的超细羟基磷灰石纳米线。由于非均相聚合使有机相和无机相很好地整合，这种具有分级结构的水凝胶可以表现出约17.84 MPa的强度和约8.97 kJ/m的断裂能等超韧机械性能，超过了天然肌肉和几乎所有合成水凝胶。此外，通过添加CPO、PVA和SA的前体诱导再聚合，可以很容易地修复受损的水凝胶。该水凝胶在水性条件下还表现出类似肌肉的旋转运动，可发展成水驱动的仿生马达。这项研究表明，无机聚合可以实现一种新型的有机-无机整合，而不是传统的有机-无机复合，并且为先进材料的设计和制造提供了一种新策略。
