Sample geometry dependency on the measured tensile properties of cellulose nanopapers
Sample geometry dependency on the measured tensile properties of cellulose nanopapers
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DOI：
10.1016/j.matdes.2017.02.081
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发表时间：
2017-05-05
影响因子：
8.4
通讯作者：
Lee, Koon-Yang
中科院分区：
文献类型：
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作者：
Hervy, Martin;Santmarti, Alba;Lee, Koon-Yang
由于目前没有标准化的测试几何形状来评估其拉伸性能，所以通常使用小型化的测试样品来测试纤维素纳米尿布的拉伸性能。在这项工作中，我们报告了测试样品的几何形状对植物来源的纤维素纳米纤维(CNF)和微生物合成的细菌纤维素(BC)纳米纤维的拉伸性能的影响。研究了四种试件的几何形状：(1)2 mm宽的小型狗骨试件；(2)5 mm宽的小型矩形试件；(3)5 mm宽的标准狗骨试件；(4)15 mm宽的标准矩形试件。结果发现，如果使用独立的应变测量系统(视频延伸仪)，CNF和BC纳米纸的拉伸弹性系数都不会受到试件几何形状的显著影响。纤维素纳米布的平均拉伸强度也受试件几何形状的影响。结果表明，试件宽度越小，纤维素纳米布的平均拉伸强度越高。这可以用最弱连接理论来描述，即纤维素纳米纤维中存在缺陷的概率随着测试样品宽度的增加而增加。讨论了CNF和BC纳米粒子的泊松比和抗断裂性能。(三)2017年提交人(S)。爱思唯尔有限公司出版。
Miniaturised test specimens are often used for the tensile testing of cellulose nanopapers as there are currently no standardised test geometries to evaluate their tensile properties. In this work, we report the influence of test specimen geometries on the measured tensile properties of plant-derived cellulose nanofibres (CNF) and microbially synthesised bacterial cellulose (BC) nanopapers. Four test specimen geometries were studied: (i) miniaturised dog bone specimen with 2 mm width, (ii) miniaturised rectangular specimen with 5 mm width, (iii) standard dog bone specimen with 5 mm width and (iv) standard rectangular specimen with 15 mm width. It was found that the tensile moduli of both CNF and BC nanopapers were not significantly influenced by the test specimen geometries if an independent strain measurement system (video extensometer) was employed. The average tensile strength of the cellulose nanopapers is also influenced by test specimen geometries. It was observed that the smaller the test specimen width, the higher the average tensile strength of the cellulose nanopapers. This can be described by the weakest link theory, whereby the probability of defects present in the cellulose nanopapers increases with increasing test specimen width. The Poisson's ratio and fracture resistance of CNF and BC nanopapers are also discussed. (C) 2017 The Author(s). Published by Elsevier Ltd.