scholarly journals Effect of Temperature of Oxalic Acid on the Fabrication of Porous Anodic Alumina from Al-Mn Alloys

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
C. H. Voon ◽  
M. N. Derman ◽  
U. Hashim ◽  
K. R. Ahmad ◽  
K. L. Foo
Keyword(s):  
Oxalic Acid ◽  
Pore Wall ◽  
Single Step ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Effect Of Temperature ◽  
Interpore Distance ◽  
Rate Of Increase ◽  
Steady State Current ◽  
Increasing Temperature

The influence of temperature of oxalic acid on the formation of well-ordered porous anodic alumina on Al-0.5 wt% Mn alloys was studied. Porous anodic alumina has been produced on Al-0.5 wt% Mn substrate by single-step anodising at 50 V in 0.5 M oxalic acid at temperature ranged from 5°C to 25°C for 60 minutes. The steady-state current density increased accordingly with the temperature of oxalic acid. Hexagonal pore arrangement was formed on porous anodic alumina that was formed in oxalic acid of 5, 10 and 15°C while disordered porous anodic alumina was formed in oxalic acid of 20 and 25°C. The temperature of oxalic acid did not affect the pore diameter and interpore distance of porous anodic alumina. Both rate of increase of thickness and oxide mass increased steadily with increasing temperature of oxalic acid, but the current efficiency decreased as the temperature of oxalic acid increased due to enhanced oxide dissolution from pore wall.

scholarly journals A Novel Method for Fabricating Double Layers Porous Anodic Alumina in Phosphoric/Oxalic Acid Solution and Oxalic Acid Solution

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Yanfang Xu ◽  
Xiaojiu Li ◽  
Hao Liu ◽  
Jie Xu
Keyword(s):  
Oxalic Acid ◽  
Acid Solution ◽  
Oxalic Acid Solution ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Double Layers ◽  
Pore Density ◽  
Interpore Distance ◽  
Small Pore ◽  
Novel Method

A novel method for fabricating ordered double layers porous anodic alumina (DL-PAA) with controllable nanopore size was presented. Highly ordered large pore layer with interpore distance of 480 nm was fabricated in phosphoric acid solution with oxalic acid addition at the potential of 195 V and the small pore layer was fabricated in oxalic acid solution at the potential from 60 to 100 V. Experimental results show that the thickness of large pore layer is linearly correlative with anodizing time, and pore diameter is linearly correlative with pore widening time. When the anodizing potential in oxalic acid solution was adjusted from 60 to 100 V, the small pore layers with continuously tunable interpore distance from 142 to 241 nm and pore density from1.94×109to4.89×109 cm−2were obtained. And the interpore distance and the pore density of small pore layers are closely correlative with the anodizing potential. The fabricated DL-PAA templates can be widely utilized for fabrication of ordered nanomaterials, such as superhydrophobic or gecko-inspired adhesive materials and metal or semiconductor nanowires.

scholarly journals Effect of Manganese Content on the Fabrication of Porous Anodic Alumina

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
C. H. Voon ◽  
M. N. Derman ◽  
U. Hashim
Keyword(s):  
Pore Diameter ◽  
Chromic Acid ◽  
Cell Structure ◽  
Manganese Content ◽  
Single Step ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Secondary Phases ◽  
Interpore Distance ◽  
Ordered Porous

The influence of manganese content on the formation of well-ordered porous anodic alumina was studied. Porous anodic alumina has been produced on aluminium substrate of different manganese content by single-step anodizing at 50 V in 0.3 M oxalic acid at 15°C for 60 minutes. The well-ordered pore and cell structure was revealed by subjecting the porous anodic alumina to oxide dissolution treatment in a mixture of chromic acid and phosphoric acid. It was found that the manganese content above 1 wt% impaired the regularity of the cell and pore structure significantly, which can be attributed to the presence of secondary phases in the starting material with manganese content above 1 wt%. The pore diameter and interpore distance decreased with the addition of manganese into the substrates. The time variation of current density and the thickness of porous anodic alumina also decreased as a function of the manganese content in the substrates.

Effect of Concentration of Oxalic Acid on the Synthesis of Porous Anodic Alumina (PAA) on Aluminum Alloy AA6061

2016 ◽  
Vol 857 ◽  
pp. 281-285
Author(s):  
Chun Hong Voon ◽  
Bee Ying Lim ◽  
K.L. Foo ◽  
Uda Hashim ◽  
Sung Ting Sam ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Oxalic Acid ◽  
Pore Size ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Edx Analysis ◽  
Interpore Distance ◽  
Ordered Porous

In this study, porous anodic alumina was formed by anodizing of aluminum alloy AA6061 in oxalic acid with concentration ranged from 0.1 M to 1.0 M respectively. AA6061 alloys were anodized at 40 V and 25°C for 60 minutes. FESEM images show that the uniformity of the pores arrangement of porous anodic alumina depends significantly on the concentration of oxalic acid. Well-ordered porous anodic alumina was formed in oxalic acid of 0.3 M, 0.5 M and 0.7 M while disordered porous anodic alumina were formed when the oxalic acid of 0.1 M and 1.0 M were used as electrolytes. EDX analysis revealed that the only peaks corresponding to aluminum and oxygen were detected. Pore size was found to increase with the concentration of oxalic acid while the interpore distance remained almost unchanged although the concentration of oxalic acid increased from 0.1 M to 0.7 M. Atypical anodic alumina without pores arrangement was formed when 1.0 M oxalic acid was used for anodizing.

Synthesis of Porous Anodic Alumina (PAA) on Aluminum Alloy AA6061 in Mixture of Phosphoric Acid and Oxalic Acid

2016 ◽  
Vol 857 ◽  
pp. 237-241
Author(s):  
Chun Hong Voon ◽  
Bee Ying Lim ◽  
K.L. Foo ◽  
Uda Hashim ◽  
Sung Ting Sam ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Oxalic Acid ◽  
Phosphoric Acid ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interpore Distance ◽  
Diffraction Patterns ◽  
Ordered Porous

In this study, porous anodic alumina was formed on aluminum alloy AA6061 by anodizing using mixture of 0.3 M oxalic acid and phosphoric acid with concentration ranged from 0.1 M to 1.0 M. AA6061 alloys were anodized at 40 V and 25°C for 60 minutes. FESEM images show that the uniformity of the pores arrangement of porous anodic alumina decreased with the increasing concentration of phosphoric acid in the electrolyte. Well-ordered porous anodic alumina was formed in mixture of 0.3 M oxalic acid and 0.1 M phosphoric acid while disordered porous anodic alumina were formed when the concentration of phosphoric acid were in the range of 0.3 M to 1.0 M. Pore size and interpore distance were found to increase with the concentration of phosphoric acid in the mixture. X-ray diffraction patterns show that to γ-Al2O3 were formed on the surface of AA6061 after the anodizing process, regardless of the concentration of phosphoric acid in the mixture electrolyte.

Light emission from silicon-based porous anodic alumina formed in 0.5 M oxalic acid

2003 ◽  
Vol 94 (4) ◽  
pp. 2407-2410 ◽  
Author(s):  
G. S. Huang ◽  
X. L. Wu ◽  
Y. Xie ◽  
X. F. Shao ◽  
S. H. Wang
Keyword(s):  
Oxalic Acid ◽  
Light Emission ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Silicon Based

Formation of Porous Anodic Alumina from Impure Aluminum Foil in Inorganic Acids

2015 ◽  
Vol 1112 ◽  
pp. 89-93
Author(s):  
Ahmad Nurrudin ◽  
Brian Yuliarto ◽  
Suyatman ◽  
Agung Sriwongo
Keyword(s):  
Room Temperature ◽  
Porous Alumina ◽  
Aluminum Foil ◽  
Average Diameter ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Sulfate Electrolyte ◽  
Average Pore ◽  
Interpore Distance ◽  
Inorganic Acids

The morphology of porous anodic alumina (PAA) formed by anodizing in inorganic electrolytes is reported. An impure aluminum was anodized in sulfuric acid, phosphoric acid and chromic acidat room temperature with a constant applied potential 2 – 30 V. The formation of porous anodic alumina was carried out by one and two steps anodization. It is clearly noted that anodizing impure aluminum at room temperature provide higher kinetic of oxide dissolution compared to oxide growth. Two steps anodizing aluminum in sulfate electrolyte always resulted in random porous alumina, while phosphate electrolyte provided strong anodization producing irregular porous alumina with average diameter of 61.6 nm. Two steps anodizing aluminum in chromate electrolyte produce better pore ordering with relatively large size pore distributions. The average pore diameter of alumina increases linearly with applied voltage, with proportionality factor lp 0.83 nmV-1. Annealing the sample increased the interpore distance, removed stresses providing lower activation energy for pore formation.

The effects of electropolishing on the nanochannel ordering of the porous anodic alumina prepared in oxalic acid

2008 ◽  
Vol 13 (2) ◽  
pp. 321-332 ◽  
Author(s):  
Abdur Rauf ◽  
Mazhar Mehmood ◽  
Muhammad Asim Rasheed ◽  
Muhammad Aslam
Keyword(s):  
Oxalic Acid ◽  
Anodic Alumina ◽  
Porous Anodic Alumina

Fabrication of Porous Anodic Alumina by Single-Step Anodization: Influence of the Molar Concentration and effect of the Chemical Etching

2019 ◽  
Vol 39 (1) ◽  
pp. 401-408
Author(s):  
Rina H. Bustamante ◽  
Daniel Raimundo ◽  
Hipólito Alan Champi ◽  
H. Y. Kim ◽  
Walter J. Salcedo
Keyword(s):  
Chemical Etching ◽  
Single Step ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Molar Concentration
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