Viscoelastic Oil Barrier Coating for Self-Healing Paint

Paints have been commonly used on infrastructure to act as a protective barrier to slow the effects of degradation. For metal structures when this protection is gone or a scratch is deep enough, corrosion proceeds which can lead to failure of the structures. To solve the issues related to corrosion, we have designed a self-healing barrier coating to possess particular rheological properties. The coating must have structural rigidity to be resilient to external stimuli while at the same time, it must also have liquid-like properties that enable flow when under shear such as when a scratch or defect occurs. After formation of the defect, fluid flow can refresh the region with new material. In this work, we discuss an oil-based suspension with microparticles to address the thixotropic requirements. The loading of reduced graphene oxide (rGO) increases the shear viscosity of the resultant oil-based suspension, providing solid-like properties. The addition of silicone oil provides lubrication for fluid-like movement of the particles and immiscibility with water, resulting in the desired self-healing property and durability. When nanoparticles like titanium dioxide are added, this increases the shear thinning capabilities and the resultant self-healing time decreases. Oil based coatings with higher mass loading of the solid rGO particles were identified as more durable in water and as more optimal at preventing metallic corrosion, when exposed to accelerated corrosive conditions.