ENCYCLOPÉDIE DE LA RECHERCHE SUR L’ALUMINIUM AU QUÉBEC 2013 | Page 54
52
NOUVEAUX PRODUITS ET MATÉRIAUX À BASE D'ALUMINIUM
NEW ALUMINIUM BASED PRODUCTS AND MATERIALS
Superhydrophobic aluminum alloy surfaces by
electrophoretic deposition process and their
SURFACES SUPERHYDROPHOBES D’ALLIAGE D’ALUMINIUM PRÉPARÉES
corrosion resistance properties
PAR DÉPÔT ÉLECTROPHORÉTIQUE ET LEUR RÉSISTANCE À LA CORROSION
SUPERHYDROPHOBIC ALUMINUM ALLOY SURFACES OBTAINED BY ELECTROPHORETIC
DEPOSITION PROCESS AND THEIR CORROSION RESISTANCE PROPERTIES
Y. Huang, D. K. Sarkar and X.-Grant Chen
Auteur 1, Author2
Centre Universitaire de Recherche sur l’Aluminium (CURAL)
1 Département et Institution 1
Université du Québec à Chicoutimi
555 Boulevard de l'Université, Chicoutimi,Québec, Canada G7H 2B1,
2 department and Institution 2.
([email protected])
1.Introduction
1.1 Superhydrophobicity in nature
1.5 What’s electrophoretic deposition (EPD)?
Superhydrophobicity in Quebec
Charged colloidal particles suspended in a liquid medium migrate under the
influence of an electric field and are deposited onto an electrode.
Young equation
1.2 What is a superhydrophobic surface?
2.Objectives
LV
Surface exhibits nearly zero wetting.
1.3 Why the surface is nearly zero wetting ?
Micro-nanorough pattern on their surface:
Large amount of air entrapment
Covered with low surface energy waxy coating:
Weaken interaction between surface and water
1.4 Applications
Vapor
SV
θ
SL
Solid
cos
Wenzel model
SV SL
LV
Cassie model
θ’
cos r cos
Anti-ice
Wiperless windshield
Drag reduction
cos f (cos 1) 1
3.Experiments
Clothing
4.Results and discussions
4.1 Preparation of superhydrophobic Al alloy surface
PRIX // AWARD
b
a
Studying the corrosion resistance property
of superhydrophobic Al surface as compared
with as-received Al surface.
θ’
PRIX // AWARD
Corrosion resistance
Preparation of superhydrophobic aluminum alloy
surfaces by electrophoretic deposition (EPD) process;
Liquid
c
30nm ZnO nanoparticles were put in 70ml mixture of 0.01 M stearic acid (SA), 2propanol and tert-butyl alcohol (vol.= 1:2:4), followed by ultrasonication for 1 h.
Anodic and cathodic aluminum alloys in the suspension with the application of 30 V
DC for 10 minutes with a range of EPD temperature (10-50 ℃).
The corrosion resistance of the samples was investigated via potentiodynamic
polarization curves acquired by electrochemical experiments in a 3.5% NaCl solution.
4.2 Corrosion resistance of superhydrophobic Al alloy surface
CA ~ 155
Ying Huang
Dilip Sarkar
X.-Grant Chen
Centre de recherche
sur l’aluminium - REGAL,
Université Laval
Figure 1 (a) TEM image of as-received 30 nm ZnO nanoparticles as provided by supplier of mknano; SEM images of cathodic surfaces of AA6061
aluminum alloy after the electrophoresis deposition at 30 V for 10minutes in stearic acid (SA) functionalized ZnO suspensions at (b) 30 ℃, (c) 50 ℃,
respectively.
30℃
a
CA ~ 94
a
b
CA~127
50℃
c
b
Electrophoretic
Contact angle
deposition
(°)
temperature (℃)
Figure 2 (a) XRD patterns of aluminum alloy substrate and electrophoretic deposited SA-functionalized ZnO thin film; (b) IRRAS
spectra of (I) pure ZnO, (II) ZnO+SA and (III) SA-functionalized ZnO films on aluminum alloy surface;
5.Conclusions
Bare copper
30
50
94±1
127±2
155±1
Corrosion
current
density jcorr
(A/cm2)
36.10
1.8
0.4
Polarization
resistance Rp
(kΩ-cm2)
1
10
158
d
Figure 3 Polarization curves of as-received aluminum alloy, SAfunctionalized ZnO thin film at 30V for 10minutes at 30 ℃ and 50 ℃,
respectively. (a) and (b) show the SEM images of as-received aluminum
alloy surface before and after corrosion test; (c) and (d) show the
superhydrophobic aluminum alloy surface before and after corrosion test.
6.Acknowledgements and publications
The one-step electrophoretic deposition (EPD) process has been utilized to prepare
superhydrophobic stearic acid functionalized ZnO nanoparticles thin films on aluminum
alloy surfaces at 30 V DC at 30℃ as well as 50 ℃, having contact angle of 127°and 155°,
respectively.
The superhydrophobic aluminum alloy surface has a lower corrosion current density of 0.4
A/cm2 and a high polarization resistance of 158kΩ-cm2 , showing a better corrosion
resistance property as compared with bare aluminum alloy surface, which has corrosion
current density of 36.1 A/cm2 and polarization resistance of only 1kΩ-cm2.
We acknowledge the financial support provided by Natural Sciences and
Engineering Research Council of Canada (NSERC), Regroupement Aluminium
(REGAL) and Centre québécois de recherche et de développement de l'aluminium
(CQRDA).
Y. Huang, D.K. Sarkar, X. –Grant Chen:
1. A One-step Process to Engineer Superhydrophobic Copper Surfaces, Materials Letters, Vol. 64 (2010)
2722;
2. Fabrication of Superhydrophobic Surfaces on Aluminum Alloy via electrodeposition of copper
followed by electrochemical modification, Nano-Micro Lett. Vol. 3 (2011) 160;
3. Preparation of Nanostructu