Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical Studies
Experimental and quantum chemical calculations have been used to study the adsorption of oleic acid on silica gel derived from rice ash hulls. Characterization of the gel showed that it had a BET specific surface area of 131.7 m 2 /g and a point of zero charge (pzc) at a pH value of 3. A maximum cap...
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2006-11-01
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Series: | Adsorption Science & Technology |
Online Access: | https://doi.org/10.1260/026361706781388978 |
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doaj-4002b79e58734be8abab6b6f6d8399172021-03-02T07:22:48ZengHindawi - SAGE PublishingAdsorption Science & Technology0263-61742048-40382006-11-012410.1260/026361706781388978Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical StudiesAsem A. Atia0Ahmed M. El-Nahas1Asmaa M. Marie2Laila D. Al Mahdy3 Chemistry Department, Faculty of Science, El-Menoufia University, Shebin El-Kom, Egypt Chemistry Department, Faculty of Science, El-Menoufia University, Shebin El-Kom, Egypt Food Technology Research Institute, Agricultural Research Center, Cairo, Egypt Food Technology Research Institute, Agricultural Research Center, Cairo, EgyptExperimental and quantum chemical calculations have been used to study the adsorption of oleic acid on silica gel derived from rice ash hulls. Characterization of the gel showed that it had a BET specific surface area of 131.7 m 2 /g and a point of zero charge (pzc) at a pH value of 3. A maximum capacity of 0.70 mmol/g was obtained for the adsorption of oleic acid onto the gel at 301 K. The free energy of adsorption, ΔG 0 301 K , was determined as −23.1 kJ/mol. The interaction of propanoic and butanoic acids as models for oleic acid with bare, mono- and di-hydrated silanol has been investigated using B3LYP and CBS-QB3 levels of theory. The dihydrated silanol model gave a ΔG 0 301 K value of −24 kJ/mol at the CBS-QB3 level which is in perfect agreement with the experimental value quoted above.https://doi.org/10.1260/026361706781388978 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Asem A. Atia Ahmed M. El-Nahas Asmaa M. Marie Laila D. Al Mahdy |
spellingShingle |
Asem A. Atia Ahmed M. El-Nahas Asmaa M. Marie Laila D. Al Mahdy Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical Studies Adsorption Science & Technology |
author_facet |
Asem A. Atia Ahmed M. El-Nahas Asmaa M. Marie Laila D. Al Mahdy |
author_sort |
Asem A. Atia |
title |
Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical Studies |
title_short |
Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical Studies |
title_full |
Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical Studies |
title_fullStr |
Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical Studies |
title_full_unstemmed |
Adsorption of Oleic Acid on Silica Gel Derived from Rice Ash Hulls: Experimental and Theoretical Studies |
title_sort |
adsorption of oleic acid on silica gel derived from rice ash hulls: experimental and theoretical studies |
publisher |
Hindawi - SAGE Publishing |
series |
Adsorption Science & Technology |
issn |
0263-6174 2048-4038 |
publishDate |
2006-11-01 |
description |
Experimental and quantum chemical calculations have been used to study the adsorption of oleic acid on silica gel derived from rice ash hulls. Characterization of the gel showed that it had a BET specific surface area of 131.7 m 2 /g and a point of zero charge (pzc) at a pH value of 3. A maximum capacity of 0.70 mmol/g was obtained for the adsorption of oleic acid onto the gel at 301 K. The free energy of adsorption, ΔG 0 301 K , was determined as −23.1 kJ/mol. The interaction of propanoic and butanoic acids as models for oleic acid with bare, mono- and di-hydrated silanol has been investigated using B3LYP and CBS-QB3 levels of theory. The dihydrated silanol model gave a ΔG 0 301 K value of −24 kJ/mol at the CBS-QB3 level which is in perfect agreement with the experimental value quoted above. |
url |
https://doi.org/10.1260/026361706781388978 |
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