scholarly journals Morphological, Chemical Surface, and Diffusive Transport Characterizations of a Nanoporous Alumina Membrane

Nanomaterials ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 2192-2202 ◽  
Author(s):  
María I. Vázquez ◽  
Virgina Romero ◽  
Victor Vega ◽  
Javier García ◽  
Victor M. Prida ◽  
...  
2013 ◽  
Vol 117 (48) ◽  
pp. 25513-25518 ◽  
Author(s):  
V. Romero ◽  
M.I. Vázquez ◽  
S. Cañete ◽  
V. Vega ◽  
J. García ◽  
...  

2021 ◽  
Vol 13 (14) ◽  
pp. 7593
Author(s):  
Farooq Khan Niazi ◽  
Malik Adeel Umer ◽  
Ashfaq Ahmed ◽  
Muhammad Arslan Hafeez ◽  
Zafar Khan ◽  
...  

Ultrafiltration membranes offer a progressive and efficient means to filter out various process fluids. The prime factor influencing ultrafiltration to a great extent is the porosity of the membranes employed. Regarding membrane development, alumina membranes are extensively studied due to their uniform porosity and mechanical strength. The present research work is specifically aimed towards the investigation of nanoporous alumina membranes, as a function of sintering parameters, on ultrafiltration performance. Alumina membranes are fabricated by sintering at various temperatures ranging from 1200–1300 °C for different holding times between 5–15 h. The morphological analysis, conducted using Scanning electron microscopy (SEM), revealed a homogeneous distribution of pores throughout the surface and cross-section of the membranes developed. It was observed that an increase in the sintering temperature and time resulted in a gradual decrease in the average pore size. A sample with an optimal pore size of 73.65 nm achieved after sintering at 1250 °C for 15 h, was used for the evaluation of ultrafiltration performance. However, the best mechanical strength and highest stress-bearing ability were exhibited by the sample sintered at 1300 °C for 5 h, whereas the sample sintered at 1250 °C for 5 h displayed the highest strain in terms of compression. The selected alumina membrane sample demonstrated excellent performance in the ultrafiltration of sugarcane juice, compared to the other process liquids.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Kang-Kyun Wang ◽  
Bong-Jin Kim ◽  
Si-Hwan Ko ◽  
Dong Hoon Choi ◽  
Yong-Rok Kim

Fabrication and photophysical study of photofunctional nanoporous alumina membrane (PNAM) were performed, and its application of photodynamic antimicrobial chemotherapy (PACT) was investigated. Nanoporous alumina membrane (NAM) was fabricated by two-step aluminium anodic oxidation process. Surface of the fabricated NAM was modified with organo-silane agent to induce covalent bonding between NAM and a photosensitizer (PtCP: [5,10,15-triphenyl-20-(4-methoxycarbonylphenyl)-porphyrin] platinum). PtCP was covalently bonded to the surface of the modified NAM by nucleophilic acyl substitution reaction process. The morphology and the photophysical properties of the fabricated PNAM were confirmed with field emission scanning electron microscope (FE-SEM), steady-state spectroscopies, and nanosecond laser-induced time-resolved spectroscopy. For the efficacy study of PNAM in PACT, an enveloped animal virus, vesicular stomatitis virus (VSV), was utilized as a target organism. Antiviral effect of the PNAM-PACT was measured by the extent of suppression of plaque-forming units (PFU) after the light irradiation. In the cultures inoculated with PACT-treated VSV, the suppression of PFU was prominent, which demonstrates that PNAM is a potential bio clean-up tool.


2009 ◽  
Vol 94 (22) ◽  
pp. 223102 ◽  
Author(s):  
Yuichi Kurashima ◽  
Yoshihiko Yokota ◽  
Iwao Miyamoto ◽  
Hiromichi Kataura ◽  
Youichi Sakakibara

Coatings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Ana Cuevas ◽  
María Martínez de Yuso ◽  
Víctor Vega ◽  
Ana González ◽  
Víctor Prida ◽  
...  

Optical changes associated with the surface coating of different metal oxides and nanolayers by the ALD technique of a nanoporous alumina structure (NPAS) obtained by the two-step anodization method were analyzed. The NPASs were coated with: (i) a single layer (SiO2 or TiO2), and (ii) a double layer of SiO2 plus Al2O3 or aluminum doped ZnO (AZO) to estimate the effect of surface layer coverage material, geometrical parameters (pore-size/porosity), and number of layers on light transmission/reflection. Chemical surface characterization of the different NPASs was carried out by analyzing XPS spectra, which allowed us to obtain an estimation of the coating layer homogeneity. Transmittance and spectroscopic ellipsometry measurements were analyzed in order to detect changes in characteristic optical parameters such as band gap, refractive index, and extinction coefficients associated with the material and the characteristics of the single or double coating layers.


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