Department of Applied Chemistry, Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan.
Biomacromolecules. 2024 Nov 11;25(11):7249-7259. doi: 10.1021/acs.biomac.4c00950. Epub 2024 Oct 12.
Molecular dynamics (MD) simulations were conducted to investigate the hydrogen-bond (H-bond) structure and its impact on the tensile strength of hydrated amorphous cellulose. The study identifies a stable intramolecular H-bond between the hydroxyl group at position 3 and the ether oxygen at position 5 (OH3···O5). Intermolecularly, the hydroxyl groups at positions 2 (OH2) and 6 (OH6) form stable H-bonds. Young's modulus, maximum tensile strength, and corresponding strain were calculated as functions of moisture content, while the H-bond network, water cluster formation, and cellulose chain orientation during tensile simulations were analyzed to elucidate mechanical properties. The substitution effect of cellulose on Young's modulus is also examined, revealing that the substitution of OH3 for a hydrophobic group minimally affects Young's modulus, but substitutions at OH2 and OH6 significantly reduce tensile strength due to their roles as key intermolecular H-bond donor sites.
采用分子动力学（MD）模拟研究了水合无定形纤维素中的氢键（H-bond）结构及其对拉伸强度的影响。研究确定了位置 3 的羟基和位置 5 的醚氧之间的稳定分子内 H-键（OH3···O5）。在分子间，位置 2（OH2）和 6（OH6）的羟基形成稳定的 H-键。杨氏模量、最大拉伸强度和相应的应变被计算为水分含量的函数，同时分析了拉伸模拟过程中的氢键网络、水团簇形成和纤维素链取向，以阐明力学性能。还研究了纤维素对杨氏模量的取代效应，结果表明，羟基 OH3 被疏水性基团取代对杨氏模量的影响最小，但羟基 OH2 和 OH6 的取代会显著降低拉伸强度，因为它们是关键的分子间 H-键供体位点。
