Department of Chemistry, 1102 Natural Sciences 2, University of California, Irvine, California 92697-2025, USA.
Nat Mater. 2014 Nov;13(11):1055-62. doi: 10.1038/nmat4090. Epub 2014 Sep 28.
For rational design of advanced polymeric materials, it is critical to establish a clear mechanistic link between the molecular structure of a polymer and the emergent bulk mechanical properties. Despite progress towards this goal, it remains a major challenge to directly correlate the bulk mechanical performance to the nanomechanical properties of individual constituent macromolecules. Here, we show a direct correlation between the single-molecule nanomechanical properties of a biomimetic modular polymer and the mechanical characteristics of the resulting bulk material. The multi-cyclic single-molecule force spectroscopy (SMFS) data enabled quantitative derivation of the asymmetric potential energy profile of individual module rupture and re-folding, in which a steep dissociative pathway accounted for the high plateau modulus, while a shallow associative well explained the energy-dissipative hysteresis and dynamic, adaptive recovery. These results demonstrate the potential for SMFS to serve as a guide for future rational design of advanced multifunctional materials.
为了合理设计先进的高分子材料,将聚合物的分子结构与新兴的整体力学性能建立明确的机械联系至关重要。尽管在这方面取得了进展,但将整体力学性能直接关联到单个组成大分子的纳米力学性能仍然是一个重大挑战。在这里,我们展示了仿生模块化聚合物的单分子纳米力学性能与所得整体材料的机械特性之间的直接相关性。多循环单分子力谱(SMFS)数据使我们能够定量推导出单个模块断裂和重新折叠的不对称势能曲线,其中陡峭的解离途径解释了高平台模量,而浅的缔合势阱则解释了能量耗散滞后和动态、自适应恢复。这些结果表明,SMFS 有可能成为未来设计先进多功能材料的指南。