Partial molar volume reduction of solvent for solute crystallization using carbon dioxide as antisolvent
DSpace at IIT Bombay
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Title |
Partial molar volume reduction of solvent for solute crystallization using carbon dioxide as antisolvent
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Creator |
MUKHOPADHYAY, M
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Subject |
expansion
gas antisolvent crystallization (gasc) partial molar volume of solvent relative partial molar volume reduction (rpmvr) solute solubility co(2) dissolution antisolvent effect |
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Description |
The gas antisolvent crystallization (GASC) process using dense carbon dioxide (CO(2)) as antisolvent is particularly useful for purification and micronization of thermo-labile bioactive solid substances. Conventionally, the GASC process is characterized by the relative total volume expansion or the relative molar volume expansion of the solution. A new criterion is proposed in this work in terms of the relative partial molar volume reduction (RPMVR) of the solvent for selection of the solvent and the optimum process condition for the GASC process, as it directly gives a measure of the fraction of the dissolved solute crystallized. The solute solubility is proportional to the partial molar volume of the solvent, (v) over bar (2) which drastically decreases at a high CO(2) dissolution. This is attributed to clustering of CO(2) molecules around the solvent molecules causing the loss of solvent power. This results in the desired antisolvent effect for lowering the solute solubility. (v) over bar (2) has been calculated for a large number of solvent-CO(2) liquid mixtures using the Peng-Robinson equation of state. It has been observed that (v) over bar (2) drastically reduces at a high value of x(1), irrespective of the fact whether the solvent density is higher or lower than that of the CO(2). The solute solubility has been predicted from its value at the ambient pressure and the ratio of the partial molar volumes of the solvent with and without CO(2) dissolved in it. The predicted solubility of beta-carotene in ethyl acetate with variation of x(1) at 298 K has been found to compare well with the experimentally observed trend of the GASC process. (C) 2002 .
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Publisher |
ELSEVIER SCIENCE BV
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Date |
2011-07-26T01:50:44Z
2011-12-26T12:52:30Z 2011-12-27T05:38:21Z 2011-07-26T01:50:44Z 2011-12-26T12:52:30Z 2011-12-27T05:38:21Z 2003 |
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Type |
Article
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Identifier |
JOURNAL OF SUPERCRITICAL FLUIDS, 25(3), 213-223
0896-8446 http://dx.doi.org/10.1016/S0896-8446(02)00147-X http://dspace.library.iitb.ac.in/xmlui/handle/10054/6852 http://hdl.handle.net/10054/6852 |
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Language |
en
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