Development of a superhydrophobic polyurethane-based coating from a two-step plasma-fluoroalkyl silane treatment

Abstract

A method of achieving a superhydrophobic surface based upon a highly filled polyurethane (PU) paint coating has been demonstrated through the use of a combined oxygen/argon plasma pretreatment and a fluoroalkyl silane (FAS) final treatment.The combined plasma-FAS treated PU surface has been investigated and characterised using: field emission gun secondary electron microscope (FEG-SEM); X-ray photoelectron spectroscopy (XPS); energy-dispersive X-ray spectroscopy (EDX); water contact angle analysis (WCA); atomic force microscopy (AFM), and;Fourier transform infrared spectroscopy (FTIR).It was found that the oxygen/argon plasma treatment increased both the surface roughness (R a ) and surface free energy (SFE) of the PU paint coating from approximately 60 to 320 nm, and, ~52 to ~80 mN/m respectively. It was also found that the plasma process created a multiscale roughened texture through the process of differential ablation between the PU polymer and the barium sulphate solid content, which is present in the paint as an extender, and other additives. In addition, the process also imparted favourable polar groups into the PU surface from the ionised and radical oxygen species in the plasma.When the FAS coating was subsequently applied to the PU without prior plasma treatment, there was a significant increase in water contact angles. This parameter increased from approximately 60° on untreated PU to around 130° with FAS applied.

Hydrophobic Leather Coating for Footwear Applications by a Low-Pressure Plasma Polymerisation Process

“…Specifically, the plasma polymerisation technology can infuse monomers into plasma and coat surfaces with ultra-thin layers, such as polymer coatings, by formation of gas-phase free radicals and their recombination at radical sites during film growth resulting in stable and durable structures [ 14 ] able to impart functional properties to a great variety of materials. Many monomers can be used for the deposition of ultra-thin films by plasma polymerisation, among which the most widely used is hexamethyldisiloxane (HMDSO) [ 9 , 10 , 11 , 15 , 16 ].…”

Biobased superhydrophobic coating enabled by nanoparticle assembly

“…36 Surface treatments oen refer to silane vapor deposition or liquid cast. [37][38][39][40][41] Surface roughness can be fabricated via colloidal lithography, 42 hot press, [43][44][45] mould, [46][47][48] and selective evaporation. 49 In addition, switchable hydrophilic and hydrophobic patterns have been designed for lotus-like self-cleaning capabilities.…”

Constructing a Dual-Function Surface by Microcasting and Nanospraying for Efficient Drag Reduction and Potential Antifouling Capabilities

“…APTES with a concentration of 5% was added and used to modify the MSN. After sonication for 5 min, a good dispersion of MSNs was achieved and the radical groups of APTES strongly bonded the nanoparticles to the substrates [21]. The dispersed nanoparticles were sprayed on the BS surface by a spraying gun.…”