Eco-Friendly and Safe Method of Fabricating Superhydrophobic Surfaces on Stainless Steel Substrates

Abstract

Industries are forced to explore more eco-friendly and safer processing methods to cope with increasing environmental issues. One of them is the fabrication of superhydrophobic stainless steel surfaces in the food industry. Current methods of fabricating superhydrophobic stainless steel surfaces have disadvantages, including using various toxic chemicals and fluorinated modifications, which cause hazards and environmental pollution, thereby limiting the application in the food industry. In this paper, an eco-friendly and safe method is proposed for fabricating superhydrophobic surfaces on stainless steel substrates using vacuum evaporation, chemical replacement reaction, and heating. The as-fabricated surface shows good superhydrophobicity with a water contact angle (WCA) of up to 155.7°as well as a water slide angle (WSA) as low as about 0°. Meanwhile, repellency to acidic and alkaline liquids, durability, self-cleaning, and antifouling properties are studied. Besides, the carbon content and its effect on wettability of the samples before and after heating at different temperatures are deeply investigated. The proposed method is an alternative approach for fabricating superhydrophobic stainless steel surfaces for application in the food industry without any environmental pollution.

Chemical Fabrication Strategies for Achieving Bioinspired Superhydrophobic Surfaces with Micro and Nanostructures: A Review

“…[ 82 ] In addition, superhydrophobic stainless steel was also fabricated through vacuum evaporation of copper film, chemical deposition of Ag, and heat treatment at 100 °C, which possessed a WCA of 155.7° and a WSA of close to 0° exhibiting resistance to acid and alkali and a self‐cleaning property. [ 83 ]…”

“…[82] In addition, superhydrophobic stainless steel was also fabricated through vacuum evaporation of copper film, chemical deposition of Ag, and heat treatment at 100 C, which possessed a WCA of 155.7 and a WSA of close to 0 exhibiting resistance to acid and alkali and a self-cleaning property. [83] In 2012, to obtain rough nickel arrays, Kang et al [84] immersed etched porous aluminum substrates into a mixed solution containing lactic acid, NaH 2 PO 2 •H 2 O, CH 3 COONa, NaHCO 3 , and NiSO 4 •6H 2 O to deposit nickel nanoparticles. And then, superhydrophobic nickel surfaces with WCA of 164 AE 2 were acquired by modifying by 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane.…”

“…[124] However, the long alkyl chains are readily hydrolyzed. [163] To prepare an environmentally-friendly and stable superhydrophobic surface, Wang et al [83] proposed the method of heating modification, in which the surface energy is reduced by carbon adsorption during heating. Therefore, these eco-friendly modification methods could be more favorable for sustainable engineering and environmentally-friendly development.…”

A Review on Applications of Superhydrophobic Materials in Civil Engineering

“…It indicated that the surface had good self‐cleaning property. To reduce environmental pollution caused by chemical reagents, Wang et al [ 70 ] produced SHPB surfaces on stainless steels by an eco‐friendly and safe method. Micro–nano structures were formed through vacuum evaporation as well as chemical reaction.…”

One-step transformation of a fluoro-based polymer into a superhydrophobic polymer composites

“…However, the water contact angle on the smooth hydrophobic surface generally does not exceed 125 o [8,9]. Nowadays, studies involving the preparation of superhydrophobic surfaces (lignocellulose nanofibrils [10], stainless steel [11], wood [12]... etc) suitable for the purpose of use are quite attractive. Superhydrophobic surfaces (> 150 o ) can be obtained by controlling the surface roughness via various processing methods, such as etching [13,14], drop evaporation [15], a gel-like porous coating [16] and spin-coating of nanoparticles dispersed in an organic solvent onto polymeric films [17].…”