Department of Chemistry, Stanford University, Stanford, CA 94305, USA.
The PULSE Institute, Stanford University, Stanford, CA 94305, USA.
Science. 2017 Aug 4;357(6350):475-479. doi: 10.1126/science.aan2797.
Biological systems sense and respond to mechanical stimuli in a complex manner. In an effort to develop synthetic materials that transduce mechanical force into multifold changes in their intrinsic properties, we report on a mechanochemically responsive nonconjugated polymer that converts to a conjugated polymer via an extensive rearrangement of the macromolecular structure in response to force. Our design is based on the facile mechanochemical unzipping of polyladderene, a polymer inspired by a lipid natural product structure and prepared via direct metathesis polymerization. The resultant polyacetylene block copolymers exhibit long conjugation length and uniform trans-configuration and self-assemble into semiconducting nanowires. Calculations support a tandem unzipping mechanism of the ladderene units.
生物系统以复杂的方式感知和响应机械刺激。为了开发能够将机械力转化为固有特性的多种变化的合成材料，我们报告了一种机械化学响应的非共轭聚合物，该聚合物通过大分子结构的广泛重排响应于力转化为共轭聚合物。我们的设计基于聚梯形烯的易机械化学解拉链，这是一种受脂质天然产物结构启发并通过直接复分解聚合制备的聚合物。所得的聚乙炔嵌段共聚物具有长共轭长度和均匀的反式构型，并自组装成半导体纳米线。计算支持梯形烯单元的串联解拉链机制。
