Superhydrophobic organic and inorganic clay nanocomposites for epoxy steel coatings

A new exfoliated superhydrophobic nanocomposite based on the modification of hydrophobic montmorillonite clay (HMT) was obtained by using hydrophobic silver and iron oxides nanoparticles. The modified HMT nanocomposites were blended with the epoxy resin and cured with polyamine hardener and easily sprayed on the rough steel surface through a facile and effective one-step spraying method. The highest seawater contact angles above 150° obtained for iron oxides/HMT blended with epoxy coating matrix. The atomic force microscope and scanning electron microscope images elucidate that the exfoliation of HMT and the production of rough surface coatings that responsible for the superhydrophobic hierarchical microstructure of iron oxides/HMT epoxy coatings. Furthermore, the porosity and agglomeration of Ag/HMT epoxy composites were responsible for the failure of their superhydrophobicity. The superhydrophobic epoxy nanocomposites were endowed with extraordinary adhesion, mechanical, chemical and abrasion resistivity via salt spray resistance to the high saline seawater environment.