Multi-Foulant-Resistant Material Design by Matching Coating-Fluid Optical Properties

Area of Science:

• Materials Science
• Surface Chemistry
• Energy Production

Background:

• Corrosion deposits, or fouling, significantly impede large-scale energy production by increasing pressure drops, reducing heat transfer, and accelerating corrosion.
• Fouling leads to system derating and premature failure in critical infrastructure like nuclear power plants and geothermal reservoirs.

Purpose of the Study:

• To investigate colloidal interactions between foulants and coated surfaces to minimize foulant adhesion.
• To test the hypothesis that matching the refractive index spectrum of a coating to its surrounding fluid reduces foulant adhesion.
• To determine if Lifshitz theory can predict multi-foulant-resistant materials.

Main Methods:

• First-principle calculations of Hamaker constants and refractive indices for six foulants on six coatings in water.
• Adhesion measurements using atomic force microscopy (AFM)-based force spectroscopy.
• Correlation of calculated properties with experimental adhesion data.

Main Results:

• Calculated Hamaker constants and refractive indices correlated well with AFM adhesion measurements.
• Coatings with refractive index spectra matching water (amorphous 2% fluorine-doped tin oxide, crystalline SiO2, CaF2, Na3AlF6) resisted adhesion of diverse foulants.
• The Lifshitz theory proved sufficient for predicting multi-foulant resistance.

Conclusions:

• Matching the refractive index spectrum of coatings to the surrounding fluid is a validated principle for minimizing foulant adhesion.
• This design principle can be applied to develop multi-fouling-resistant coatings for systems where van der Waals forces dominate adhesion.
• The findings offer a pathway to enhance the longevity and efficiency of energy production systems susceptible to fouling.