Corrosion is a major problem faced by the automobile/transport industry. To overcome corrosion,
the industry relies on surface coatings in which metal coatings (Zn, Cr etc.) and polymers
(polyurethane, epoxy, etc.) are widely recommended. However the presence of localized defects
is unavoidable, hence corrosion proceeds. To self-heal or arrest the corrosion progress at local
defects on any coating, smart coating is adopted as a strategy.
The smart coating includes the incorporation of self-healing particles that would respond to the
external stimuli such as pH, temperature, UV and light, thereby inhibiting corrosion and
increasing coating life. Such a self-healing particle can be achieved by the synthesis of porous
silica which acts as a container and loading of different corrosion inhibitors namely green,
organic, inorganic, and hybrid into it. This particle incorporated smart coating can potentially
acts as a replacement for chromate coatings.
The current work describes the synthesis of porous silica using a three-step solvo-thermal
process. The smart coating development includes template preparation, loading with an organic
corrosion inhibitor, followed by polymer encapsulation. The synthesized porous silica was
characterized for morphological features, porosity, and surface charge. The release kinetics of
inhibitor before and after the polymer encapsulation was studied using UV-Visible technique at
two different pH values (7 and 11). The polymer encapsulated inhibitor-loaded porous silica was
incorporated in a metallic coating (namely Zn) and in an epoxy matrix. The release and corrosion
inhibition performance of these coatings were studied using various electrochemical techniques.