Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study
Isothermal titration calorimetry (ITC) was used to study interactions between water vapour and the surface of thermally converted sodium bicarbonate (NaHCO3). The decarboxylation degree of the samples was varied from 3% to 35% and the humidity range was 54â100%. The obtained enthalpy values were all...
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| Format: | Article |
| Language: | English |
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Elsevier
2013-06-01
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| Series: | Journal of Pharmaceutical Analysis |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S209517791200144X |
| _version_ | 1818440645844402176 |
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| author | Natalia Volkova Henri Hansson Lennart Ljunggren |
| author_facet | Natalia Volkova Henri Hansson Lennart Ljunggren |
| author_sort | Natalia Volkova |
| collection | DOAJ |
| description | Isothermal titration calorimetry (ITC) was used to study interactions between water vapour and the surface of thermally converted sodium bicarbonate (NaHCO3). The decarboxylation degree of the samples was varied from 3% to 35% and the humidity range was 54â100%. The obtained enthalpy values were all exothermic and showed a positive linear correlation with decarboxylation degrees for each humidity studied. The critical humidity, 75% (RHo), was determined as the inflection point on a plot of the meanâÎHkJ/mole Na2CO3 against RH. Humidities above the critical humidity lead to complete surface dissolution. The water uptake (m) was determined after each calorimetric experiment, complementing the enthalpy data. A mechanism of water vapour interaction with decarboxylated samples, including the formation of trona and Wegscheiderâs salt on the bicarbonate surface is proposed for humidities below RHo. Keywords: Isothermal titration calorimetry, Sodium bicarbonate, Sodium carbonate, Trona salt, Wegscheiderâs salt, Enthalpy, Relative humidity, Pyrolytic decarboxylation |
| first_indexed | 2024-12-14T18:15:39Z |
| format | Article |
| id | doaj.art-017722561b9344d598cda119088d18b6 |
| institution | Directory Open Access Journal |
| issn | 2095-1779 |
| language | English |
| last_indexed | 2024-12-14T18:15:39Z |
| publishDate | 2013-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Pharmaceutical Analysis |
| spelling | doaj.art-017722561b9344d598cda119088d18b62022-12-21T22:52:11ZengElsevierJournal of Pharmaceutical Analysis2095-17792013-06-0133193199Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric studyNatalia Volkova0Henri Hansson1Lennart Ljunggren2Department of Biomedical Science, Malmö University, SE-205 06, Malmö, Sweden; Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden; Corresponding author at: Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, Getingevägen 60, 22241 Lund, Sweden. Tel.: +46 46 222 47 41; fax: +46 46 222 47 13.Galenica AB, Medeon Science Park, SE-205 12, Malmö, SwedenDepartment of Biomedical Science, Malmö University, SE-205 06, Malmö, SwedenIsothermal titration calorimetry (ITC) was used to study interactions between water vapour and the surface of thermally converted sodium bicarbonate (NaHCO3). The decarboxylation degree of the samples was varied from 3% to 35% and the humidity range was 54â100%. The obtained enthalpy values were all exothermic and showed a positive linear correlation with decarboxylation degrees for each humidity studied. The critical humidity, 75% (RHo), was determined as the inflection point on a plot of the meanâÎHkJ/mole Na2CO3 against RH. Humidities above the critical humidity lead to complete surface dissolution. The water uptake (m) was determined after each calorimetric experiment, complementing the enthalpy data. A mechanism of water vapour interaction with decarboxylated samples, including the formation of trona and Wegscheiderâs salt on the bicarbonate surface is proposed for humidities below RHo. Keywords: Isothermal titration calorimetry, Sodium bicarbonate, Sodium carbonate, Trona salt, Wegscheiderâs salt, Enthalpy, Relative humidity, Pyrolytic decarboxylationhttp://www.sciencedirect.com/science/article/pii/S209517791200144X |
| spellingShingle | Natalia Volkova Henri Hansson Lennart Ljunggren Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study Journal of Pharmaceutical Analysis |
| title | Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study |
| title_full | Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study |
| title_fullStr | Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study |
| title_full_unstemmed | Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study |
| title_short | Thermally decarboxylated sodium bicarbonate: Interactions with water vapour, calorimetric study |
| title_sort | thermally decarboxylated sodium bicarbonate interactions with water vapour calorimetric study |
| url | http://www.sciencedirect.com/science/article/pii/S209517791200144X |
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