Micro/nanostructured ZnO-based superhydrophobic steel surface with enhanced corrosion protection

Abstract

This paper presents a simple process of fabricating a superhydrophobic carbon steel surface with high water repellence and good corrosion resistance. The steel surface was covered by thin ZnO layers via various methods of sol-gel method, hydrothermal synthesis, and electrochemical deposition, then further functionalised with methyltrichlorosilane. Morphological features observed by a scanning electron microscope (SEM) show that ZnO layers are composed of micro/nanostructures. Furthermore, the chemical composition of these films has been analysed by an energy dispersive X-ray spectroscopy (EDX). An optimum experimental condition, based on the type of Zn deposition method, has been obtained to provide superhydrophobic properties with a water contact angle of 152 ± 2o. In a 3.5 wt% NaCl solution, the corrosion resistance properties of the superhydrophobic ZnO-coated steel are found to be very good with an anti-corrosion efficiency of 93.12%.

Omniphobic carbon steel surface with good wax-repellent performance

“…Note that the maximum water contact angle on "a perfected smooth and chemical homogeneous surface" is about 130 o [8]. Similar to water, based on the contact angle of liquid having a low surface tension (such as oil, alcohol, or another organic solvent), the surface can be categorised as superomniphilic, ominiphilic and omniphobic [6,10].…”

“…The steel substrate is firstly dipped into 0.1 M HCl solution for 30 seconds before the zinc electrodeposition process is conducted for different time durations: 5 minutes, 15 minutes, 30 minutes, 45 minutes, and 60 minutes. More details concerning this process are described in our previous article [10,18].…”