Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic Strength
We describe the effects of NaOH/SiO2 ratio and pH on the formation of mesoporous materials, which was synthesized via an alkali-metal hydroxide fusion method, from amorphous silica dissolved in NaOH. Physical properties (e.g., specific surface area, pore volume, and pore size) of mesoporous material...
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2012-01-01
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doaj-8c0506b1fbbd4ba99db6c42d40eedac32020-11-24T22:58:03ZengHindawi LimitedJournal of Nanomaterials1687-41101687-41292012-01-01201210.1155/2012/528174528174Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic StrengthJayhyun Park0Yosep Han1Hyunjung Kim2R&D Team, Institute of Mine Reclamation Corporation, Coal Center, 30 Chungjin-dong, Jongno-gu, Seoul 110-727, Republic of Korea Department of Natural Resources and Environmental Engineering, Hanyang University, number 17 Heangdang-dong, Seongdong-gu, Seoul 133-791, Republic of Korea Department of Mineral Resources and Energy Engineering, Chonbuk National University, 664-14 Duckjin-dong 1Ga, Duckjin-gu, Jeonju, Jeonbuk 561-756, Republic of KoreaWe describe the effects of NaOH/SiO2 ratio and pH on the formation of mesoporous materials, which was synthesized via an alkali-metal hydroxide fusion method, from amorphous silica dissolved in NaOH. Physical properties (e.g., specific surface area, pore volume, and pore size) of mesoporous materials synthesized at different conditions (i.e., pH, NaOH/SiO2 ratio) were evaluated through X-ray diffraction, nitrogen adsorption-desorption, and transmission electron microscope analyses. The results showed that, at the NaOH/SiO2 ratios of 0.5, 1, and 2, gels were successfully synthesized while no product was formed at the NaOH/SiO2 ratios greater than 2. Additionally, mesoporous materials were found to be formed at both pH 10 and 11 while they were unstable under more alkaline conditions. The adsorption/desorption isotherm results for the mesoporous materials synthesized at around pH 11 and with NaOH/SiO2 ratios of 0.5–0.8 showed a hysteresis loop characteristic of the bottle-neck pore shape. Furthermore, mesoporous materials with good physical properties were synthesized from all gels at pH 10 regardless of sodium concentration.http://dx.doi.org/10.1155/2012/528174 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jayhyun Park Yosep Han Hyunjung Kim |
spellingShingle |
Jayhyun Park Yosep Han Hyunjung Kim Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic Strength Journal of Nanomaterials |
author_facet |
Jayhyun Park Yosep Han Hyunjung Kim |
author_sort |
Jayhyun Park |
title |
Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic Strength |
title_short |
Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic Strength |
title_full |
Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic Strength |
title_fullStr |
Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic Strength |
title_full_unstemmed |
Formation of Mesoporous Materials from Silica Dissolved in Various NaOH Concentrations: Effect of pH and Ionic Strength |
title_sort |
formation of mesoporous materials from silica dissolved in various naoh concentrations: effect of ph and ionic strength |
publisher |
Hindawi Limited |
series |
Journal of Nanomaterials |
issn |
1687-4110 1687-4129 |
publishDate |
2012-01-01 |
description |
We describe the effects of NaOH/SiO2 ratio and pH on the formation of mesoporous materials, which was synthesized via an alkali-metal hydroxide fusion method, from amorphous silica dissolved in NaOH. Physical properties (e.g., specific surface area, pore volume, and pore size) of mesoporous materials synthesized at different conditions (i.e., pH, NaOH/SiO2 ratio) were evaluated through X-ray diffraction, nitrogen adsorption-desorption, and transmission electron microscope analyses. The results showed that, at the NaOH/SiO2 ratios of 0.5, 1, and 2, gels were successfully synthesized while no product was formed at the NaOH/SiO2 ratios greater than 2. Additionally, mesoporous materials were found to be formed at both pH 10 and 11 while they were unstable under more alkaline conditions. The adsorption/desorption isotherm results for the mesoporous materials synthesized at around pH 11 and with NaOH/SiO2 ratios of 0.5–0.8 showed a hysteresis loop characteristic of the bottle-neck pore shape. Furthermore, mesoporous materials with good physical properties were synthesized from all gels at pH 10 regardless of sodium concentration. |
url |
http://dx.doi.org/10.1155/2012/528174 |
work_keys_str_mv |
AT jayhyunpark formationofmesoporousmaterialsfromsilicadissolvedinvariousnaohconcentrationseffectofphandionicstrength AT yosephan formationofmesoporousmaterialsfromsilicadissolvedinvariousnaohconcentrationseffectofphandionicstrength AT hyunjungkim formationofmesoporousmaterialsfromsilicadissolvedinvariousnaohconcentrationseffectofphandionicstrength |
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