When it comes to experimentation with carbon dioxide solubility, finding the right solvent can be challenging. The ideal solvent should have the lowest possible solubility of carbon dioxide under usual pressure and temperature conditions (for example, at 1 atm and 293 K). Although several publications have explored this topic, finding the perfect solution has remained elusive.
Exploring Existing Research
One study by Weiss[1] indicated that salty water has a lower solubility of carbon dioxide than pure water, making it an ideal candidate for this purpose. However, research on several organic solvents like acetone, cyclohexane, ethanol, and methanol made it apparent that they dissolve more carbon dioxide than water, making them unsuitable options for low solubility needs[2]. Lipid bilayer membranes and organic solvents such as olive or linseed oil have also been researched, but they seem to have a higher solubility coefficient than water[3].
Although finding an organic solvent with an optimal carbon dioxide solubility has been unsuccessful, considering all possible options is necessary.
Polar vs. Aprotic Solvents
When it comes to solvents, the rule of thumb, like dissolves like, is crucial. Since carbon dioxide is a nonpolar molecule, a highly polar solvent would be the worst choice. Water’s polarity could initially make it seem like a viable choice, especially when salt is added to reduce the solubility of carbon dioxide.
However, the dissociation of CO2 gas into carbonate and hydrogen ions in aqueous solutions cautions against its use. An aprotic solvent like dimethyl sulfoxide, which doesn’t carry out this conversion, could be a good solution. Comparing water (molar fraction 0.00061) and dimethyl sulfoxide (molar fraction 0.0091) and studying their polarity, dielectric constants, and dipole moments can help determine which is a more favorable option.
Deeper Dive into Dimethyl Sulfoxide Use
DMSO has a higher solubility for carbon dioxide than water, which may seem unexpected at first glance. But the dipole moment of DMSO, which is 3.96 D, is nearly twice as high as that of water. DMSO is an aprotic solvent, which means it doesn’t donate hydrogen ions, and the hydrogen-bonding ability of DMSO is lower than that of water because it lacks OH bonds.
The unique properties of DMSO, making it a useful solution for carbon dioxide solubility, can also lead to some potential issues. DMSO has a high viscosity and boiling point, both of which may be problematic depending on the experiments’ requirements.
Conclusion
In conclusion, finding the ideal solvent for low carbon dioxide solubility requires careful consideration of several factors, including polarity, dissociation, dielectric constants, and dipole moments. While water with added salt is a good starting point, considering aprotic solvents like DMSO can provide better options. However, it is crucial to examine all properties and potential issues before deciding on a final choice.
References
Weiss, R. F. Carbon Dioxide in Water and Seawater: The Solubility of a Non-Ideal Gas. Marine Chemistry 1974, 2 (3), 203–215. https://doi.org/10/cb6n2j.
Carbon Dioxide in Non-Aqueous Solvents at Pressures Less than 200 kPa; Fogg, P. G., Clever, H. L., Eds.; Solubility data series; Pergamon Press: Oxford, 1992. ISBN 978-0-08-040495-0. PDF
Simon, S. A.; Gutknecht, J. Solubility of Carbon Dioxide in Lipid Bilayer Membranes and Organic Solvents. Biochimica et Biophysica Acta (BBA) – Biomembranes 1980, 596 (3), 352–358. https://doi.org/10/bj647m.
Searching For a Solvent With a Low Carbon Dioxide Solubility
When it comes to experimentation with carbon dioxide solubility, finding the right solvent can be challenging. The ideal solvent should have the lowest possible solubility of carbon dioxide under usual pressure and temperature conditions (for example, at 1 atm and 293 K). Although several publications have explored this topic, finding the perfect solution has remained elusive.
Exploring Existing Research
One study by Weiss[1] indicated that salty water has a lower solubility of carbon dioxide than pure water, making it an ideal candidate for this purpose. However, research on several organic solvents like acetone, cyclohexane, ethanol, and methanol made it apparent that they dissolve more carbon dioxide than water, making them unsuitable options for low solubility needs[2]. Lipid bilayer membranes and organic solvents such as olive or linseed oil have also been researched, but they seem to have a higher solubility coefficient than water[3].
Although finding an organic solvent with an optimal carbon dioxide solubility has been unsuccessful, considering all possible options is necessary.
Polar vs. Aprotic Solvents
When it comes to solvents, the rule of thumb, like dissolves like, is crucial. Since carbon dioxide is a nonpolar molecule, a highly polar solvent would be the worst choice. Water’s polarity could initially make it seem like a viable choice, especially when salt is added to reduce the solubility of carbon dioxide.
However, the dissociation of CO2 gas into carbonate and hydrogen ions in aqueous solutions cautions against its use. An aprotic solvent like dimethyl sulfoxide, which doesn’t carry out this conversion, could be a good solution. Comparing water (molar fraction 0.00061) and dimethyl sulfoxide (molar fraction 0.0091) and studying their polarity, dielectric constants, and dipole moments can help determine which is a more favorable option.
Deeper Dive into Dimethyl Sulfoxide Use
DMSO has a higher solubility for carbon dioxide than water, which may seem unexpected at first glance. But the dipole moment of DMSO, which is 3.96 D, is nearly twice as high as that of water. DMSO is an aprotic solvent, which means it doesn’t donate hydrogen ions, and the hydrogen-bonding ability of DMSO is lower than that of water because it lacks OH bonds.
The unique properties of DMSO, making it a useful solution for carbon dioxide solubility, can also lead to some potential issues. DMSO has a high viscosity and boiling point, both of which may be problematic depending on the experiments’ requirements.
Conclusion
In conclusion, finding the ideal solvent for low carbon dioxide solubility requires careful consideration of several factors, including polarity, dissociation, dielectric constants, and dipole moments. While water with added salt is a good starting point, considering aprotic solvents like DMSO can provide better options. However, it is crucial to examine all properties and potential issues before deciding on a final choice.
References