Self-Healing Corrosion-Control Coatings: An Enabling Technology To Restore Aging Water Infrastructure and Permit Alternative Water Use for Cooling

Problem Statement: Most of the Nation’s water infrastructure is aging rapidly. Reports indicate that in the major water systems, approximately 30 percent of the pipes are 40 to 80 years old, and approximately 10 percent are more than 80 years old. The water pipes are subject to internal and external corrosion, resulting in pipe leaks and water main breaks. In addition to aging, the rapidly growing need to use alternate water sources for non-potable application also requires development of corrosion protection for pipelines. These alternate water sources contain high levels of dissolved salts, ammonia, and other constituents that can corrode the piping materials. Currently available corrosion-control materials do not have the self-healing ability and hence, have limited life span. To date, chromium is the only commonly used corrosion-control agent that has self-healing characteristics. Use of chromium for waste water treatment is now banned, however, due to its negative health effects. A cost-effective and environmentally benign corrosion-control measure is required to extend the lifespan of aging water infrastructure and facilitate use of alternate water sources. Technology Description: In this study, NEI Corporation proposes to overcome the problem of corrosion by developing a self-healing nanocomposite surface treatment to protect the piping materials even at high contaminant concentrations. This material has demonstrated barrier properties and damage responsive behavior for sodium chloride and water diffusion under marine (3% salt) conditions. The formulations will be optimized to provide self-healing corrosion protection against other corrosion-causing constituents in this study. Anticipated Results: A successful Phase I program will allow NEI Corporation to integrate the self-healing surface treatment to existing copper, copper alloys, and carbon steel pipes to enable protection against ammonia and dissolved salts. The overall objective of this project is to develop optimum corrosion protection formulations against different water quality constituents and piping materials. It is anticipated that the proposed application will extend the infrastructure life, lower the rehabilitation cost, and facilitate use of alternate water sources. Potential Environmental Benefits: Corrosion control by self-healing treatment can significantly prolong water infrastructure life. To date, chromium is the only commonly used corrosion-control agent that has self-healing characteristics. Chromium, however, is toxic to human health and the environment. The proposed self-healing nanocomposite material is environmentally benign and not expensive. Furthermore, this technology allows the use of an alternate source for non-potable applications, thereby making precious fresh water sources available to meet the increasing demand.