Midya Jiarul, Cang Yu, Egorov Sergei A, Matyjaszewski Krzysztof, Bockstaller Michael R, Nikoubashman Arash, Fytas George
Institute of Physics , Johannes Gutenberg University Mainz , Staudingerweg 7 , 55128 Mainz , Germany.
Max Planck Institute for Polymer Research , Ackermannweg 10 , 55128 , Mainz , Germany.
Nano Lett. 2019 Apr 10;19(4):2715-2722. doi: 10.1021/acs.nanolett.9b00817. Epub 2019 Mar 29.
The linear elastic properties of isotropic materials of polymer tethered nanoparticles (NPs) are evaluated using noncontact Brillouin light spectroscopy. While the mechanical properties of dense brush materials follow predicted trends with NP composition, a surprising increase in elastic moduli is observed in the case of sparsely grafted particle systems at approximately equal NP filling ratio. Complementary molecular dynamics simulations reveal that the stiffening is caused by the coil-like conformations of the grafted chains, which lead to stronger polymer-polymer interactions compared to densely grafted NPs with short chains. Our results point to novel opportunities to enhance the physical properties of composite materials by the strategic design of the "molecular architecture" of constituents to benefit from synergistic effects relating to the organization of the polymer component.
利用非接触布里渊光谱法评估了聚合物拴系纳米颗粒（NP）各向同性材料的线性弹性特性。虽然致密刷状材料的机械性能随NP组成呈现出预测的趋势，但在NP填充率大致相等的情况下，稀疏接枝颗粒系统的弹性模量却出现了惊人的增加。补充性的分子动力学模拟表明，这种硬化是由接枝链的线圈状构象引起的，与短链的密集接枝NP相比，这种构象导致了更强的聚合物-聚合物相互作用。我们的结果指出了通过对成分的“分子结构”进行战略设计来增强复合材料物理性能的新机会，以便从与聚合物组分组织相关的协同效应中受益。
