Disentangling the Role of Chain Conformation on the Mechanics of Polymer Tethered Particle Materials
Disentangling the Role of Chain Conformation on the Mechanics of Polymer Tethered Particle Materials
复制标题
DOI：
10.1021/acs.nanolett.9b00817
复制
发表时间：
2019-04-01
期刊：
影响因子：
10.8
通讯作者：
Fytas, George
中科院分区：
文献类型：
--
作者：
Midya, Jiarul;Cang, Yu;Fytas, George
采用非接触式布里渊光谱分析方法，研究了聚合物系留纳米颗粒(NPs)各向同性材料的线弹性。虽然致密刷子材料的力学性能遵循预测的趋势，但在接枝稀疏的颗粒体系中，当NP填充比例大致相同时，弹性模量会有惊人的增加。互补分子动力学模拟表明，刚性是由接枝链的卷曲构象引起的，与短链的密集接枝纳米粒子相比，这种构象导致了更强的聚合物-聚合物相互作用。我们的结果指出了新的机会，通过战略性设计成分的“分子结构”来增强复合材料的物理性能，从而受益于与聚合物成分的组织有关的协同效应。
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.