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

L. W. Zhang, M. F. Kai, X. H. Chen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)

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.

Original languageEnglish
Article number103522
JournalCement and Concrete Composites
Volume109
DOIs
Publication statusPublished - May 2020
Externally publishedYes

Keywords

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

ASJC Scopus subject areas

  • Building and Construction
  • Materials Science(all)

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