Journal article
Electrochemical and mechanical properties of superhydrophobic aluminum substrates modified with nano-silica and fluorosilane
Surface & coatings technology, Vol.206(17), pp.3700-3713
04/25/2012
Handle:
https://hdl.handle.net/2376/121127
Abstract
Nano-silica particles were deposited on acid-etched hydrophilic aluminum (Al) substrates by immersion in well-dispersed nano-silica aqueous suspension and tetramethylamonium hydroxide, followed by a heat treatment. The surface was then further treated by a reaction with fluorosilane. The hydrophobicity, surface morphology, and mechanical properties of the coated Al substrates were investigated, along with their electrochemical properties over time of exposure to two NaCl solutions (0.3% and 3% by weight). All the coated Al surfaces exhibited a water contact angle of 155–158°, i.e., superhydrophobicity. The use of nano-silica suspension significantly enhanced the hydrophobicity of the coated Al. Artificial neural networks were used to provide quantitative understanding in how the microstructure of the treated Al surface contributed to its superhydrophobicity and electrochemical properties. When Ra, total (nano-roughness+micro-roughness) exceeds 450nm, WCA is greater than 154°, independent of the nano/micro-roughness ratio (RRNM). FESEM and AFM images of these surfaces suggest that a rough two-length-scale hierarchical structure coupled with the low surface energy of fluorosilane topcoat led to the superhydrophobicity of the formed coatings. The coating prepared with the 0.2% nano-silica suspension (vs. other concentrations) featured the highest Young's modulus and the best corrosion protection to the Al substrate in both NaCl solutions.
► Used ANNs to quantify the microstructure underlying the superhydrophobicity. ► Used ANNs to analyze the electrochemical properties of the treated Al surfaces. ► A total of nano- and micro-roughness of 450nm to 500nm was desired. ► Their ratio of less than 0.25 was desired for corrosion resistance in salt brine. ► The 0.2% nano-silica suspension gave the Al surface the best treatment.
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Details
- Title
- Electrochemical and mechanical properties of superhydrophobic aluminum substrates modified with nano-silica and fluorosilane
- Creators
- Xianming Shi - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan, 430023, ChinaTuan Anh Nguyen - Corrosion and Sustainable Infrastructure Laboratory, Western Transportation Institute, PO Box 174250, Montana State University, Bozeman, MT 59717-4250, USAZhiyong Suo - Imaging and Chemical Analysis Laboratory, Department of Physics, Montana State University, Bozeman, MT 59717, USAJianlin Wu - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan, 430023, ChinaJing Gong - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan, 430023, ChinaRecep Avci - Imaging and Chemical Analysis Laboratory, Department of Physics, Montana State University, Bozeman, MT 59717, USA
- Publication Details
- Surface & coatings technology, Vol.206(17), pp.3700-3713
- Academic Unit
- Civil and Environmental Engineering, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900612711001842
- Language
- English
- Resource Type
- Journal article