Glutamine-reinforced silica gel microassembly as protective coating for aluminium surface

The present article comprises the formation of novel glutamine reinforced silica gel microassembly over aluminium and the use thereof as promising protective coating. The aluminium sheets were immersed in a glutamine solution and then in silica gel solutions with four different concentrations. Epichlorohydrin as coupling agent and Ca2+ ions as crosslinking agents were introduced in dropwise addition. Formation of monolayer and bilayer thin films, verified by inhibition efficiency and surface morphology, demonstrated successful protective coating of aluminum surface against severe corrosive environment for prolonged time. In monolayer, maximum inhibition efficiency obtained was 98.3% at 10 °C using silica gel concentration = 1200 ppm. Higher activation energy, enthalpy and entropy of activation obtained at higher silica gel concentration. The adsorption process demonstrated appropriate Langmuir isotherm fit. The formation of layer-by-layer comprises firm and stable thin films over aluminium surface with inhibition efficiency ∼99%. Such coatings performed by building-up construction have some guideline specifics that include simplicity, low cost manufacturing, and superior corrosion protection.