Lang Ryan J, Merling Weston L, Simmons David S
Department of Polymer Engineering, The University of Akron, 250 South Forge Street, Akron, Ohio 44325-0301, United States.
ACS Macro Lett. 2014 Aug 19;3(8):758-762. doi: 10.1021/mz500361v. Epub 2014 Jul 23.
We employ molecular dynamics simulations of nanolayered polymers to systematically quantify the dependence of nanoconfinement effects on interfacial energy and the "softness" of confinement. Results indicate that nanoconfined depends linearly on interfacial adhesion energy, with a slope that scales exponentially with the ratio of the bulk Debye-Waller factors ⟨⟩ of the confined and confining materials. These trends, together with a convergence at low interfacial adhesion energy to the of an equivalent freestanding film, are captured in a single functional form, with only three parameters explicitly referring to the confined state. The observed dependence on ⟨⟩ indicates that softness of nanoconfinement should be defined in terms of the relative high frequency shear moduli, rather than low frequency moduli or relaxation times, of the confined and confining materials.
我们采用纳米层状聚合物的分子动力学模拟来系统地量化纳米限域效应与界面能以及限域“柔软度”之间的依赖关系。结果表明，纳米限域效应与界面粘附能呈线性关系，其斜率随受限材料和限域材料的体德拜 - 瓦勒因子⟨⟩之比呈指数缩放。这些趋势，连同在低界面粘附能下向等效独立膜的[此处原文缺失相关内容]的收敛，都以单一函数形式体现，其中只有三个参数明确涉及受限状态。观察到的对⟨⟩的依赖表明，纳米限域的柔软度应根据受限材料和限域材料的相对高频剪切模量来定义，而不是低频模量或弛豫时间。
