Polymer mechanochemistry has emerged as a unique approach to regulate homogeneous catalysis in chemical transformations. The utilization of polymer mechanochemistry to regulate heterogeneous catalysis, however, still remains to be investigated. In this study, using polymer-grafted gold nanoparticles as the model heterogeneous catalysts, we show that polymer chains can be mechanically ruptured from the surface of gold nanoparticles, and thus, the catalytic activity of gold nanoparticles can be accelerated under sonication. The mechanical activation of polymer-grafted gold nanoparticles only occurs when the grafted polymer chains exceed a threshold molecular weight. This mechanical behavior is similar to those mechanophore-linked polymers. More importantly, further characterizations reveal that the Au–Au bonds instead of the Au–S bonds are broken at the heterointerfaces of polymer chains and gold nanoparticles. Our study unveils an unprecedented characteristic of polymer-grafted metallic nanoparticles in response to external mechanical stress.

中文翻译：

---

用高分子力学化学调控金纳米粒子的多相催化

聚合物机械化学已成为一种独特的方法来调节化学转化中的均相催化。然而，利用聚合物机械化学来调节多相催化仍有待研究。在这项研究中，使用聚合物接枝的金纳米粒子作为模型非均相催化剂，我们表明聚合物链可以从金纳米粒子表面机械断裂，因此可以在超声处理下加速金纳米粒子的催化活性。聚合物接枝的金纳米粒子的机械活化仅在接枝聚合物链超过阈值分子量时发生。这种机械行为类似于那些机械载体连接的聚合物。更重要的是，进一步的表征表明，在聚合物链和金纳米粒子的异质界面处，Au-Au 键而不是 Au-S 键被破坏。我们的研究揭示了聚合物接枝的金属纳米粒子响应外部机械应力的前所未有的特性。