Si-doped graphene in geopolymer : Its interfacial chemical bonding, structure evolution and ultrastrong reinforcing ability

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

Detail(s)

Original languageEnglish
Article number103522
Journal / PublicationCement and Concrete Composites
Volume109
Online published29 Jan 2020
Publication statusPublished - May 2020

Abstract

Low-cost synthesis of silicon-doped graphene (Si-graphene) is attractive for the development of new graphene/ geopolymer nanocomposites. In this work, a new insight into the properties of Si-graphene and the working mechanisms of Si-graphene in geopolymer is provided via molecular dynamics simulations. It is shown that Si- doping deteriorates the mechanical properties of graphene as Si-doping creates point defects, but it improves the surface hydrophilicity, which promotes its dispersion in aqueous media. By studying the polymerization process of Al(OH)4/Si(OH)4 monomers on Si-graphene, it is found that Si-graphene can be chemically bonded with geopolymer matrix by typical condensation reactions. Structural analysis reveals that the interfacial bonding has a beneficial effect on condensing the geopolymer composites, due to a denser interphase region. The tensile test reveals that the Young’s modulus of 10% Si-graphene/geopolymer nanocomposites is twice larger than that of graphene/geopolymer nanocomposites. In addition, the interfacial bonding can strengthen the interfacial structure and arrest crack formation in geopolymer matrices.

Research Area(s)

  • Si-doped graphene in geopolymer, Interfacial chemical bonding, Interphase structure, Ultrastrong reinforcing ability