Swelling and dimensional stability of xyloglucan/montmorillonite nanocomposites in moist conditions from molecular dynamics simulations

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• 作者：Yan Wang^a ; Malin Bergenstrå ; hle-Wohlert^b ; ^c ; Yaoquan Tu^a ; Hans Å ; gren^a ; Lars A. Berglund^b ; ^c ; Jakob Wohlert^b ; ^c ; ^jacke@kth.se
• 关键词：Clay ; Hemicellulose ; Biocomposite ; Moisture ; Computer simulations
• 刊名：Computational Materials Science
• 出版年：2017
• 出版时间：15 February 2017
• 年：2017
• 卷：128
• 期：Complete
• 页码：191-197
• 全文大小：3007 K
• 卷排序：128

文摘

Nacre-mimetic biocomposites made from the combination of montmorillonite clay and the hemicellulose xyloglucan give materials that retain much of their material properties even at high relative humidity. Here, a model composite system consisting of two clay platelets intercalated by xyloglucan oligomers was studied at different levels of hydration using molecular dynamics simulations, and compared to the pure clay. It was found that xyloglucan inhibits swelling of the clay at low water contents by promoting the formation of nano-sized voids that fill with water without affecting the material’s dimensions. At higher water contents the XG itself swells, but at the same time maintaining contact with both platelets across the gallery, thereby acting as a physical cross-linker in a manner similar to the role of XG in the plant cell wall.