Moghimikheirabadi Ahmad, Karatrantos Argyrios V, Kröger Martin
Polymer Physics, Department of Materials, ETH Zurich, Leopold-Ruzicka-Weg 4, CH-8093 Zurich, Switzerland.
Materials Research and Technology, Luxembourg Institute of Science and Technology, 5, Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg.
Polymers (Basel). 2021 Nov 19;13(22):4001. doi: 10.3390/polym13224001.
We explore the behavior of coarse-grained ionic polymer nanocomposites (IPNCs) under uniaxial extension up to 800% strain by means of nonequilibrium molecular dynamics simulations. We observe a simultaneous increase of stiffness and toughness of the IPNCs upon increasing the engineering strain rate, in agreement with experimental observations. We reveal that the excellent toughness of the IPNCs originates from the electrostatic interaction between polymers and nanoparticles, and that it is not due to the mobility of the nanoparticles or the presence of polymer-polymer entanglements. During the extension, and depending on the nanoparticle volume fraction, polymer-nanoparticle ionic crosslinks are suppressed with the increase of strain rate and electrostatic strength, while the mean pore radius increases with strain rate and is altered by the nanoparticle volume fraction and electrostatic strength. At relatively low strain rates, IPNCs containing an entangled matrix exhibit self-strengthening behavior. We provide microscopic insight into the structural, conformational properties and crosslinks of IPNCs, also referred to as polymer nanocomposite electrolytes, accompanying their unusual mechanical behavior.
我们通过非平衡分子动力学模拟，研究了粗粒化离子聚合物纳米复合材料（IPNCs）在单轴拉伸至800%应变下的行为。我们观察到，随着工程应变率的增加，IPNCs的刚度和韧性同时提高，这与实验观察结果一致。我们发现，IPNCs优异的韧性源于聚合物与纳米颗粒之间的静电相互作用，而非纳米颗粒的迁移率或聚合物-聚合物缠结的存在。在拉伸过程中，根据纳米颗粒的体积分数，聚合物-纳米颗粒离子交联随着应变率和静电强度的增加而受到抑制，而平均孔径随应变率增加，并受纳米颗粒体积分数和静电强度的影响而改变。在相对较低的应变率下，含有缠结基质的IPNCs表现出自增强行为。我们对IPNCs（也称为聚合物纳米复合电解质）的结构、构象性质和交联进行了微观洞察，同时揭示了它们不同寻常的力学行为。
