期刊
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
卷 78, 期 -, 页码 526-539出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmps.2015.02.012
关键词
Carbohydrates; Interfaces; Adhesion; Biopolymers; Nanocomposites; Biomaterials
资金
- Army Research Office [W911NF-13-1-0241]
- Northwestern University High Performance Computing Center
- Department of Defense (DoD) through the National Defense Science and Engineering Graduate Fellowship (NDSEG) Program
Cellulose nanocrystals (CNCs) are one of nature's most abundant structural material building blocks and possess outstanding mechanical properties including a tensile modulus comparable to Kevlar. It remains challenging to upscale these properties in CNC neat films and nanocomposites due to the difficulty of characterizing interfacial bonding between CNCs that governs stress transfer under deformation. Here we present new analyses based on atomistic simulations of shear and tensile failure of the interfaces between I beta CNCs, providing new insight into factors governing the mechanical behavior of hierarchical nanocellulose materials. We compare the two most relevant crystal interfaces and find that hydrogen bonded surfaces have greater tensile strength compared to the surfaces governed by weaker interactions. On the contrary, shearing simulations reveal that friction between the atomic interfaces depends not only on surface energy but also the energy landscape along the shear direction. While being a weaker interface, the intersheet plane exhibits greater energy barriers to shear. The molecular roughness of this interface, characterized by a greater energy barrier, exhibits stick-slip deformation behavior as opposed to a more continuous sliding and rebonding mechanism observed for the interfaces with hydrogen bonds. Analytical models to describe the energy landscapes are developed using energy scaling relations for van der Waals surfaces in combination with a modification of the Prandtl-Tomlinson model for atomic friction. Our simulations pave the way for tailoring hierarchical CNC materials by taking a similar approach to techniques employed for describing metals, where mechanical properties can be tuned through a deeper understanding of grain boundary physics and nanoscale interfaces. (C) 2015 Published by Elsevier Ltd.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据