Anti-corrosion Properties of Functionalized Organo-silane coupling agents on Interstitial Free (IF) Steel in Simulated Saline solution

Abstract

The selection of precursors for silane-based anti-corrosive coatings to protect steel is challenging to obtain in a few experiments as the protection performance varies with types of precursor molecule and surface of metal substrates. The coating performance of precursors was predicted through quantum chemical calculations (Density Functional Theory (DFT) where DFT parameters such as hardness (ƞ), dipole moment (µ), and the number of electrons transferred (∆N) to metal substrate enabling us to choose suitable silane coupling agents. DFT study and experimental validation reveals that precursor containing functional groups like -NH2, -SH, and -O- offers better protection against corrosion to galvanized IF steel compared to those without functional moiety. The order of corrosion inhibition is MPTMS (1M) ≈ APTES (1A) > GPTMS (1G) > TEOS(1T).