SBIR Phase I: Superhydrophobic Zinc Coatings for Anti-Corrosion Applications

P & P Coating, Blacksburg CA

Investigators

Abstract

This Small Business Innovation Research Phase I project aims to develop a superhydrophobic zinc coating that is expected to exhibit higher anti-corrosion performance than existing zinc coatings. Existing zinc coatings easily get wet and, consequently, their anti-corrosion performance is significantly reduced. As a result, these coatings are often treated with an additional layer of hexavalent chromate to improve their anti-corrosion performance. However, hexavalent chromium is a human carcinogen, which has been targeted for elimination by environmental regulations. Existing substitutes to this material provide lower performance at a higher cost and thus are not fully accepted in the industry. The superhydrophobic coating to be developed in this effort prevents water from wetting the surface. Therefore, this coating is expected to exhibit higher corrosion resistance without the need for the additional hexavalent chromate coating. This new coating, therefore, represents an eco-friendly replacement for the zinc coating treated with hexavalent chromate, and potentially exhibits higher anti-corrosion performance than existing alternatives. The proposed development can be adopted in the $370 million target market of US zinc coatings. The intellectual merit of this project includes developing superhydrophobic zinc coatings based on the technology invented by the company founders. Most existing superhydrophobic coatings are made of non-metallic materials such as polymers or ceramics, and therefore are not feasible for the proposed application. The superhydrophobic zinc coating provides a transformative solution for the corrosion problem when a metallic coating is required. The main objective of the proposed Phase I research is developing a superhydrophobic zinc coating, which eliminates the need for the hexavalent chromate treatment. This development is expected to provide corrosion protection equivalent, or superior, to that provided by the chromate-treated zinc coatings. The anti-corrosion properties of the superhydrophobic coating will be evaluated using salt spray tests and electrochemical techniques. In addition, durability of the superhydrophobic zinc coating will be investigated using the standard abrasion test.