标题： 玻璃状界面通过增强应变下的渗流驱动体积膨胀来增强弹性体纳米复合材料 显示英文标题

标题： Glassy interphases reinforce elastomeric nanocomposites by enhancing percolation-driven volume expansion under strain

摘要： 近一个世纪以来，将纳米颗粒引入弹性体已产生了极其坚韧的纳米复合材料，这些材料对从执行器到轮胎的技术至关重要。 然而，这种增强发生的机制仍然是材料科学中的一个核心开放问题。 一种广泛争论的假设认为，聚合物与颗粒之间的强相互作用会引发“玻璃状桥接”，将颗粒粘合形成一个连通的网络，从而抵抗拉伸。 在这里，分子动力学模拟表明，玻璃状颗粒外壳并不主要提供拉伸粘合性。 相反，它们放大了一个基本机制，即填料和弹性体网络之间的竞争导致弹性体在变形时体积增加。 这引发了弹性体体模量的贡献，其数量级比其杨氏模量大1000倍。 这些发现确立了填充弹性体低应变增强的统一理解，即源于共存颗粒网络和弹性体网络之间的体积竞争。 这重新定义并统一了我们对低应变增强的理解，为玻璃状桥接的存在提供了明确的诊断方法，并为坚韧的弹性体纳米复合材料提供了一种新的设计原则。 显示英文摘要

摘要： For nearly a century, introduction of nanoparticles to elastomers has yielded extraordinarily tough nanocomposites that are critical to technologies from actuators to tires. The mechanisms by which this reinforcement occurs have nevertheless remained a central open question in material science. One widely debated hypothesis posits that strong interactions between polymer and particles induce "glassy bridges" that cement particles into a cohesive percolating network that resists elongation. Here, molecular dynamics simulations show that glassy particle shells do not primarily provide elongational cohesion. Instead, they amplify an underlying mechanism wherein competition between filler and elastomer networks causes the elastomer's volume to increase on deformation. This induces contributions from the elastomer's bulk modulus, which is of order 1000 times larger than its Young's modulus. These findings establish a unified understanding of low-strain reinforcement in filled elastomers as emanating from volumetric competition between coexisting particulate and elastomeric networks. This reframes and unifies our understanding of low-strain reinforcement, provides a clear-cut diagnostic for the presence of glassy bridging, and offers a new design principle for tough elastomeric nanocomposites.