近日，美国南佛罗里达大学Pierre Kawak团队报道了玻璃界面相通过增强应变下的体积膨胀来增强弹性纳米复合材料。该研究于2026年4月13日发表在《美国科学院院刊》杂志上。

近一个世纪以来，向弹性体中引入纳米颗粒制备出了极具韧性的纳米复合材料，这些材料对于从致动器到轮胎等诸多技术至关重要。然而，这种增强作用的机制一直是材料科学中一个核心的未解之谜。一个被广泛争论的假说认为，聚合物与颗粒之间的强相互作用会诱导形成“玻璃态桥接”，这些桥接将颗粒粘合成一个具有内聚力的逾渗网络，从而抵抗拉伸。

研究组通过分子动力学模拟表明，玻璃态的颗粒壳层并不主要提供拉伸内聚力。相反，它们放大了一种潜在机制：填料网络与弹性体网络之间的竞争导致弹性体在形变时体积增加。这便引入了弹性体体积模量的贡献，其数值比杨氏模量高出约1000倍。这些发现建立了一个统一的理解：填充弹性体的低应变增强源于共存的颗粒网络与弹性体网络之间的体积竞争。这一观点重塑并统一了我们对低应变增强的认识，为判断玻璃态桥接的存在提供了明确的诊断依据，并为设计韧性弹性体纳米复合材料提供了设计原则。

附：英文原文

Title: Glassy interphases reinforce elastomeric nanocomposites by enhancing volume expansion under strain

Author: Kawak, Pierre, Bhapkar, Harshad, Simmons, David S.

Issue&Volume: 2026-4-13

Abstract: 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 1,000 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 design principle for tough elastomeric nanocomposites.

DOI: 10.1073/pnas.2528108123

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2528108123