Nanostructured ceramic coatings engineered for reduction of corrosion, erosion, fouling and viscous drag in industrial pipes and tubes

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Steel structures such as reactor vessels, pipelines, boilers and industrial tubing are heavily used in the oil and gas industry, power generation, and in manufacturing for heating & transporting fluids. These structures are often subjected to erosion, corrosion and fouling effects. Erosion and corrosion are degradation mechanisms which result in frequent structural repair and maintenance. Scale formation lowers heat transfer efficiency in boilers & heat exchangers, and increases drag in pipelines. In demanding applications such as acid digestion vessels, polytetrafluoroethylene (PTFE) [a.k.a. TEFLON] coating is used on the inner side of the steel structure. PTFE coating protects tubing due to its chemical inertness, and through its highly amphiphobic (universal liquid repellent) property. The super-amphiphobic characteristic prevents fouling by discouraging the nucleation of organic and inorganic precipitates on PTFE-coated surfaces. The challenges facing the large-scale application of PTFE coatings include its high cost, low wear-resistance (being a soft material), and its poor heat transfer property. We address these challenges with our new idea of Ceramic Teflon coatings. Recently, we published a preliminary study where the super-amphiphobic characteristic of the proposed Ceramic Teflon coating was confirmed. Our idea here consists of using nanostructured Titanium Dioxide (TiO2) in combination with ultrathin conformal coatings of perfluorinated alkanephosphonic acids. TiO2 being a ceramic, is very hard and resists erosion. TiO2 is also chemically resistant to a broad spectrum of acids and bases, being vulnerable only to hydrofluoric acid. The perfluorinated organic thin film makes the overall coating liquid repellent. The nanostructuring of the TiO2 enables liquid-repellent Cassie-Baxter-type wetting states to form. The objectives of this proposal are therefore to build, test and implement Ceramic Teflon coated pipe structures in order to demonstrate and quantify their abilities to resist erosion, corrosion, fouling and reduce viscous drag. Thus, our application has a strong fundamental research component while also being of immediate commercial significance.