Molecular dynamics simulations on adhesion of epoxy-silica interface in salt environment
YL Yaphary and ZC Yu and RHW Lam and D Hui and D Lau, COMPOSITES PART B-ENGINEERING, 131, 165-172 (2017).
Epoxy-silica interface exists in various types of newly built as well as aging concrete structures which include flooring and anchoring systems. Sea environment and deicing salt often let the concrete structures be exposed to sodium chloride solution. It is observed from the laboratory evaluation that such exposure often leads to the poor bond durability of epoxy-concrete interface. Yet, there is still a lack of such fundamental understanding as the existing investigations are merely limited to macroscale or mesoscale. Indeed, bond at the interface is governed by the interactions between dissimilar materials lying at the atomistic scale, where atomistic modeling and molecular dynamics simulations can effectively reflect the mechanical behaviors of the bilayer interface. Herein, molecular dynamics simulations together with Bell's model are employed to evaluate the effect of sodium chloride solution on the adhesion at interface between epoxy and silica. It is shown that sodium chloride solution weakens the adhesion significantly. This finding indicates that the bond deterioration at epoxy-concrete interface is critical in the presence of salt solution, which must be considered in the engineering design strategy for offshore and marine structures. (C) 2017 Elsevier Ltd. All rights reserved.
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