Superhydrophobic and Highly Oleophobic Zinc Sheet Surfaces Developed by a Simple Technique

Abstract

In this report, superhydrophobic and highly oleophobicmicro-nano-scale roughened Zn sheet surfaces were obtained.A simple and environmentally friendly technique of immersing Zn sheets in hot deionized water was used to grow ZnO nanorods.Variation of the immersion time had a significant impact on the evolution and formation of the nanorods.After their concealing with long chain fluorocarbon oligomers of 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PFDTS), ZnO nanorod surfaces prepared at 60 min immersion time showed the highest wetting repellency properties toward water and peanut oil.However the surfaces yet to be able to super repel the two liquids.In order to improve the Zn sheet surfaces repellency toward liquids with various surface tensions, hierarchical structures with the combination of both micro channels covered-up with ZnO nanorods were developed.Simple technique of one-directional mechanical sanding was used to impart micro channeled structures onto Zn sheet surfaces and post immersion in hot de-ionized water for ZnO nanorods cover-up.The concealed micro-nano-combination structures with 1H, PFDTS oligomers showed superhydrophobic and highly oleophobic properties.Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Photoluminescence (PL) techniques were used to characterize the morphology of the prepared surfaces.