Rapid and tunable growth of well-ordered hexagonal nanoporous anodic aluminum oxide (AAO) structure by two step high temperature anodization

2021 ◽  
Author(s):  
Kashif Azher ◽  
Maaz Akhtar ◽  
Shao-Fu Chang ◽  
Shih-Hsun Chen
Keyword(s):  
High Temperature ◽  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Pure Aluminum ◽  
Aluminum Substrate ◽  
Nanoporous Structure ◽  
Average Pore ◽  
Cross Sectional ◽  
Anodic Aluminum ◽  
Nano Channel

In this study, we have developed a swift and well-ordered growth of the Anodic Aluminum Oxide (AAO) nanoporous structure by two-step high temperature anodization of pure Aluminum substrate. The pre-anodization surface treatment of the aluminum substrate assists in the formation of well-organized nanoporous structures. The two-step anodization process was performed in 0.3 M of oxalic acid at 20 °C for 40 V and 45 V to obtain tunable pore diameters. The high temperature of the electrolyte solution helps in the rapid growth of the AAO nanoporous structure. The top surface image of AAO shows a well-ordered nanoporous structure with an average pore diameter of 70 nm at 40 V and 100 nm at 45 V. The SEM cross sectional view also illustrates the well-ordered nano channel and the elemental mapping elaborates the presence of aluminum and oxygen. The thickness of the AAO nanoporous structure was determined by using SEM for three anodization time spans (20, 24 and 28 hours), in which an increasing trend was observed. The fabricated AAO has a higher thickness and a well-ordered nanoporous structure that shows it can be used as a template for fabricating nanostructured materials.

The nanoporous structure of anodic aluminum oxide fabricated on the Au/Nb/Si substrate

2009 ◽  
Vol 29 (4) ◽  
pp. 1156-1160 ◽  
Author(s):  
Xiaowei Zhao ◽  
Ung-Ju Lee ◽  
Seok-Kyoo Seo ◽  
Kun-Hong Lee
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Nanoporous Structure ◽  
Si Substrate ◽  
Anodic Aluminum

Fabrication of Low Cost Membrane from Anodic Aluminum Oxide

2017 ◽  
Vol 751 ◽  
pp. 363-367
Author(s):  
Peerawith Sumtong ◽  
Apiluck Eiad-Ua
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Average Pore Diameter ◽  
Process Conditions ◽  
Low Grade ◽  
Pore Density ◽  
Average Pore ◽  
Anodic Aluminum ◽  
Interpore Distance

Anodic Aluminum Oxide (AAO) membrane has been successfully fabricated from two-step anodization with aluminum low grade (Al6061). The pore density, the pore diameter, and the interpore distance can be controlled by varying anodization process conditions. However, there are limits to control the mechanical strength and growth of AAO arrays, such as pore density, pore diameter and interpore distance. In this research the self-organized two-step anodization is carried out varying time at 24, 48 and 72 hours, respectively with 40V at the low temperature 2-5°C. The optimum conditions of AAO with two-step anodization is 40V for 48 hr. Finally, AAO substrate is separated from aluminum low-grade and enlarged pore diameter with pore widening process by 5% H3PO4. The physical properties were investigated by mean of field emission scanning electron microscope (FE-SEM) show that the average pore diameter and average interpore distance increase with the anodization time. Al6061 Aluminum substrate can be used to fabricate a nanoporous AAO film with an average pore diameter and average interpore distance larger than 70 and 90 nanometers, respectively but less mechanical stability.

scholarly journals A Modified Interposer Fabrication Process by Copper Nano-Pillars Filled in Anodic Aluminum Oxide Film for 3D Electronic Package

2018 ◽  
Vol 8 (11) ◽  
pp. 2188 ◽  
Author(s):  
Chunjin Hang ◽  
He Zhang ◽  
Yanhong Tian ◽  
Chenxi Wang ◽  
Yuan Huang ◽  
...  
Keyword(s):  
High Temperature ◽  
Aluminum Oxide ◽  
Seed Layer ◽  
Anodic Aluminum Oxide ◽  
Pore Filling ◽  
Electronic Package ◽  
Electrodeposition Process ◽  
Anodic Aluminum Oxide Film ◽  
Anodic Aluminum ◽  
Reduction Processes

Though copper nano-pillars (CNPs) filled in anodic aluminum oxide (AAO) film has been developed for many years, the high pore-filling percentage in AAO is still a bottleneck. We have demonstrated a new electrodeposition method to fill CNPs in AAO without the seed layer which is required in the traditional electrodeposition process. CNPs with uniform heights were obtained and the pore-filling percentage reached up to 97.5%. Low current density is beneficial for the high pore-filling percentage due to the uniform growing rate in different nanoscale pores. The high temperature increased the diffusion velocity of ions and enhanced the pore filling percentage but also corroded the AAO film simultaneously. Results showed that CNPs grains with <220> orientation were fabricated. Electrodeposition with low electric current could contribute to the forming of CNPs with (220) preferred orientation due to the promotion of dehydration reduction processes. The thermal conductivities of Cu-AAO interposers reaches 92.34 W/(m·K) and 3.19 W/(m·K) in vertical and horizontal directions, respectively.

Nanoporous Anodic Aluminum Oxide (AAO) Thin Film Fabrication with Low-Grade Aluminium

2016 ◽  
Vol 872 ◽  
pp. 152-156
Author(s):  
Peerawith Sumtong ◽  
Apiluck Eiad-Ua ◽  
Khattiya Chalapat
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Average Pore Diameter ◽  
Process Conditions ◽  
Low Grade ◽  
Average Pore ◽  
Aluminium Substrate ◽  
Anodization Time ◽  
Anodic Aluminum

Anodic aluminum oxide (AAO) is well known for its nanoscopic structures and its applications in microfluidics, sensors and nanoelectronics. The pore density, the pore diameter, and the interpore distance of an AAO substrate can be controlled by varying anodization process conditions. In this research, the self-organized two-step anodization is carried out with a low-grade (Al6061) aluminium substrate using a 40V voltage at the temperature of 2 to 5 °C. Three experiments are done with the anodization time of 24 hours, 48 hours and 72 hours. The structural features of AAO are characterized by a field emission electron microscope (FE-SEM). The data from FE-SEM show that the average pore diameter increases with the anodization time, and that the Al6061 aluminium substrate can be used to fabricate a nanoporous AAO film with an average pore diameter smaller than 17 nanometers.

One-Step Anodization Preparation and Photoluminescence Property of Anodic Aluminum Oxide with Nanopore Arrays

2010 ◽  
Vol 663-665 ◽  
pp. 272-275
Author(s):  
Wen Bin Yang ◽  
Xiao Hong Tang
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Oxygen Vacancies ◽  
Pure Aluminum ◽  
Photoluminescence Property ◽  
Aluminum Foil ◽  
Honeycomb Structure ◽  
Anodic Aluminum ◽  
Nanopore Arrays ◽  
One Step

Anodic aluminum oxide (AAO) film with nanopore arrays was prepared by one-step anodization of highly pure aluminum foil. Morphology, structure and photoluminescence property of AAO were characterized. Results showed that AAO owned honeycomb structure which was characterized by close-packed arrays of columnar hexagonal cells, each containing a central pore normal to the substrate. There were three peaks at around 370, 385 and 470 nm in the PL spectrum of AAO, which should be mainly attributed to the oxygen vacancies.

Fabrication of Thinner Anodic Aluminum Oxide Based Microchannels

2012 ◽  
Vol 550-553 ◽  
pp. 2046-2050 ◽  
Author(s):  
Mahadi Hasan ◽  
Ajab Khan Kasi ◽  
Jafar Khan Kasi ◽  
Nitin Afzulpurkar ◽  
Supanit Porntheeraphat ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Ph Value ◽  
Membrane Thickness ◽  
Average Pore ◽  
Wall Width ◽  
Fluid Filtration ◽  
Anodic Aluminum ◽  
Filtration System

When thickness of a membrane reduces its mechanical properties go down but thinner the membrane better the performance of the membrane in terms of filtration. In this research we fabricated a fluid filtration system with a very thin anodic aluminum oxide (AAO) membrane. The system consists of microchannels at one side of membrane while other side is flat. For both sides inlet and outlet are given. The system can facilitate two types of fluid to flow at two sides of membrane for filtration. The membrane thickness achieved was 4 μm. The average pore diameter was 50 nm. The nanopores inside the membrane are highly straight and perpendicular to the surface. The fabricated channel and wall width was 200 µm and 100 µm successively. The pillars in between microchannels hold the membrane which is termed as partial freestanding alumina (PFA) and thereby retain desired mechanical properties of the membrane. The system was tested for diffusion between DI water and salted water. The DI water was flowed in channels and salted water on other side of membrane. The pH value of DI water changed after flow. Due to channel walls, AAO membrane fabricated in this system can tolerate more pressure which leads it to be used for convective flow by applying higher pressure gradient.

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