%0 Journal Article
%T Superstrong Noncovalent Interface between Melamine and Graphene Oxide
%J -
%D 2019
%R https://doi.org/10.1021/acsami.9b02971
%X There have been growing academic interests in the study of strong organic molecule每graphene [or graphene oxide (GO)] systems, owing to their essential noncovalent nature and the consequent chemomechanical behavior within the interface. A more recent experimental measurement [Chem2018,4, 896每910] reported that the melamine每GO interface exhibits a remarkable noncovalent binding strength up to ‵1 nN, even comparable with typical covalent bonds. But the poor understanding on the complex noncovalent nature in particular makes it challenging to unveil the mystery of this high-performance interface. Herein, we carry out first-principles calculations to investigate the atomistic origin of ultrastrong noncovalent interaction between the melamine molecule and the GO sheet, as well as the chemomechanical synergy in interfacial behavior. The anomalous O每H﹞﹞﹞N hydrogen bonding, formed between the triazine moiety of melamine and the ˋOH in GO, is found cooperatively enhanced by the pin-like NH2每羽 interaction, which is responsible for the strong interface. Following static pulling simulations validates the 1 nN level rupture strength and the contribution of each noncovalent interaction within the interface. Moreover, our results show that the ˋOH hydrogen bonding will mainly augment the interfacial adhesion strength, whereas the ˋNH2 group cooperating with the ˋOH hydrogen bonding and conjugating with the GO surface will greatly improve the interfacial shear performance. Our work deepens the understanding on the chemomechanical behaviors within the noncovalent interface, which is expected to provide new potential strategies in designing high-performance graphene-based artificial nacreous materials
%U https://pubs.acs.org/doi/10.1021/acsami.9b02971