Graphene based anticorrosive coatings for Cr(vi) replacement

Abstract

Corrosion has been a perennial issue of concern for the steel industry. Chromate conversion coatings are well known pre-treatment coatings for steel but due to environmental concerns and legislations, their use has been restricted. The industrial community, pegged by these legislations, has been long demanding an economically viable and eco-friendly pre-treatment coating alternative, without having to compromise on the durability and corrosion performance of the overall coating system. The present study focuses on evaluation of graphene as an anticorrosive alternative to Cr(VI) based coatings. Graphene, produced by a high shear liquid exfoliation route, upon functionalisation, provides a conductive and nearly impermeable barrier coating. On electrochemical and coating performance evaluation of this coating system, a dramatic improvement in corrosion resistance is observed. The study confirms the environment friendly corrosion protection of steel using functionalised graphene coating.

Fundamental Insights into the Covalent Silane Functionalization of NiFe Layered Double Hydroxides

“…In addition, a N−H band is observed for APTES at about 1630 cm −1 . At lower wavenumbers, the bands in the 1100–1000 cm −1 region are related to additional Si‐O‐Si and Si‐O‐C bands . The description of the FTIR spectra for the NiFe‐DS and NiFe‐AQ samples can be found in previously published work, in which their main vibrational bands are reported .…”

Synergic enhancement of the anticorrosion properties of an epoxy coating by compositing with both graphene and halloysite nanotubes

“…The shift toward the anodic direction of E corr and the decrease in I corr both indicated better anticorrosive behavior in the coatings . E corr is usually used to define the corrosion susceptibility of a material, and the shift in E corr toward the anodic direction suggested a corrosion‐inhibiting ability . Likewise, I corr is an important parameter in assessing the corrosion resistance of coatings; that is, the smaller I corr is, the better the anticorrosion performance is .…”

Graphene-based anticorrosive coatings for copper

“…The authors believe that the protonated amino groups of hydrolyzed APTES attack the edge carbon atoms of graphene to form a C-N bond, as mentioned earlier. 20 However, as the concentration of APTES is very low, it is difficult to detect the presence of this band via FTIR or XPS analysis. Alternatively, the -OH group of hydrolyzed APTES could attack the basal plane carbon atoms of graphene to form a C-O-Si covalent bond.…”

“…These peaks diminish upon hydrolysis and condensation, whereas the Si-O-Si stretching vibration peak at 1050 cm À1 is observed prominently. 20 Moreover, two close peaks at 2860 cm À1 and 2930 cm À1 represent the symmetric and asymmetric vibrations of CH 2 groups occurring in the alkyl chains of APTES and narrow down in the case of hydrolysed APTES, respectively. 23 The graphene FTIR spectrum shows a C-C stretching peak at around 1600 cm À1 .…”