Molecular dynamics simulation of graphene oxide composite cement-based materials
The abundant oxygen-containing functional groups at the edges of graphene oxide(GO)have better reactivity and can effec-tively enhance the performance of cement-based materials.This article investigates the influence of various oxygen-containing func-tional groups in graphene oxide on the properties of cement-based materials,and establishes GO/C-S-H,GO carboxyl/C-S-H,GO hy-droxyl/C-S-H,and GO epoxy/C-S-H models.Using molecular dynamics methods to study the mechanical parameters,interfacial ad-sorption energy,and dynamic characteristics of composite materials.The results showed that the addition of GO increased the Young's modulus of the composite material by 10.7％and the Poisson's ratio by 12％.The epoxy group in GO contributes to the stability of the composite material interface,while the hydroxyl group contributes to a tighter interatomic interaction within the composite material.The calcium oxygen bond between oxygen-containing functional groups and calcium atoms is one of the sources of cohesion.The order of calcium oxygen bond lengths is Ca-OH＜Ca-O＜Ca-COOH,and the interaction force between hydroxyl groups and calcium atoms in GO is the main source of cohesion.Hydroxyl and carboxyl groups can increase the mass transfer rate of water and calci(u)m atoms,which is beneficial for the hydration reaction.
NETL
NSTL
万方数据
