Concordia University, Canada
Title: Developing super hydrophobic copper/graphene nano-platelets coatings by plasma spraying
Biography: Tahmineh Forati
Water vapor condensation is frequently used as an effective method of transferring heat using drop-wise condensation on non-wetting surfaces demonstrating enhanced heat transfer when compared to film-wise condensation. The aim of this study is to develop hierarchical surface morphologies on superhydrophobic coatings with high water repellency and mobility using atmospheric plasma spraying (APS). The novelty of this work lies in the processing of the plasma sprayed copper/graphene nano-platelets (GNPs) composite coatings. Retention of the GNPs was made successful by controlling the plasma power and particle injection angle to minimize the temperature and consequently prevent the combustion of GNPs. Several coatings were developed with different surface morphologies. By isolating the effect of surface chemistry using a stearic acid treatment the significance and effect of the achieved morphologies on the wetting behavior of the coatings were investigated. Experimental results demonstrated that coatings produced by the APS process showed excellent water repellency and water mobility: water contact angles as high as 162° as well as water sliding angles less than 1° were achieved due to the hierarchical roughness attributed to the submicron size particles in the feedstock. Moreover, results indicated that Cu/GNPs is a promising surface coating to promote dropwise condensation of water in industrial conditions due to its robust chemical stability with the potential for scalable applications while maintaining low thermal resistance.