Superhydrophobic polymers solution processing

Luo, C, Zuo, X, Wang, L, Wang, E, Song, S, Wang, J, Fan, C, Cao, Y. 2008. Flexible carbon nanotube-polymer composite films with high conductivity and superhydrophobicity made by solution process. Nano Lett 8 4454-4458. 

Another widely used approach in this area is a sol-gel process. In order to create surface roughness after deposition of thin films, a secondary component is included in the sol-gel deposition process which can be removed later by dissolution in hot water or sublimation. The removal of the secondary components gives porous structures. Subsequent lluorinated silane coating can render these sol-gel processed films superhydrophobic [81-83]. Microporous structures can be created through phase separation of organic polymer solutions and then used as a template for sol-gel processing of porous silica substrates. Ruorosilane treatment of these substrates produces superhydrophobic surfaces [84]. 

Electrospinning can create surface textures needed for superhydrophobicity. Electrospinning is a widely used technique to make ultra-thin polymer fibers. In this process, a polymer solution is charged in a capillary tube and electrically biased with respect to a grounded collector surface located 10 cm from the needle. The polymer solution is then ejected from the capillary into a jet form and the solvent evaporates leaving polymer fibers. By electrospinning polymers with hydrophobic properties, one can easily produce superhydrophobic fiber mats on the collector [89-92]. Of course, the electrospinning can also be used to make porous fiber mats... 

Suspensions of hydrophobic polymers loaded with nanoparticles, such as fluo-ropolymer loaded with carbon black, carbon nanotubes, graphene nanoplatelets and their combinations, can be solution processed into superhydrophobic... 

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