Morita Mayu, Oya Yutaka, Kato Nobuhiko, Mori Kazuki, Koyanagi Jun
Department of Materials Science and Technology, Graduate School, Tokyo University of Science, Tokyo 125-8585, Japan.
Research Institute for Science & Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
Polymers (Basel). 2022 Jun 25;14(13):2579. doi: 10.3390/polym14132579.
In this study, the atomistic-scale mechanisms affecting the interfacial stability of a thermoplastic polymer/graphene oxide interface are investigated using molecular dynamics simulations. Different combinations of thermoplastic polymers (polyethersulfone (PES) and polyetherimide (PEI)) and graphene oxides modified with -O-, -OH, and -COOH are prepared. PES is found to be more strongly stabilized with modified/functionalized graphene oxide in the order of -COOH, -OH, -O-, which is opposite to the stability order of PEI. Our results suggest that these orders of stability are governed by a balance between the following two factors resulting from electrostatic interactions: (1) atoms with a strong charge bias attract each other, thereby stabilizing the interface; (2) the excluded-volume effect of the functional groups on graphene oxide destabilizes the interface by preventing π-π stacking of aromatic rings.
在本研究中，使用分子动力学模拟研究了影响热塑性聚合物/氧化石墨烯界面稳定性的原子尺度机制。制备了热塑性聚合物（聚醚砜（PES）和聚醚酰亚胺（PEI））与用 -O-、-OH 和 -COOH 修饰的氧化石墨烯的不同组合。发现 PES 与修饰/功能化氧化石墨烯的稳定性更强，顺序为 -COOH、-OH、-O-，这与 PEI 的稳定性顺序相反。我们的结果表明，这些稳定性顺序由静电相互作用产生的以下两个因素之间的平衡决定：（1）具有强电荷偏差的原子相互吸引，从而稳定界面；（2）氧化石墨烯上官能团的体积排除效应通过阻止芳环的 π-π 堆积使界面不稳定。
