Hansen Solubility Parameters
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Hansen Solubility Parameters were developed by Charles Hansen as a way of predicting if one material will dissolve in another and form a solution [1]. They are based on the idea that like dissolves like where one molecule is defined as being 'like' another if it bonds to itself in a similar way.
Specifically, each molecule is given three Hansen parameters, each generally measured in 
:
The energy from dispersion bonds between molecules
The energy from polar bonds between molecules
The energy from hydrogen bonds between molecules
These three parameters can be treated as co-ordinates for a point in three dimensions. The nearer two molecules are in this three dimensional space, the more likely they are to dissolve into each other.
[edit] Limitations
The following limitations were acknowledged by Charles Hansen:
- The parameters will vary with temperature
- The parameters are an approximation. Bonding between molecules is more subtle than the three parameters suggest. Molecular shape is relevant. As are other types of bonding such as induced dipole, metallic and electrostatic interactions.
- The size of the molecules also plays a significant role in whether two molecules actually dissolve in a given period
- The parameters are hard to measure
[edit] External links
- Hansen solvent map Link
[edit] References
- ^ Hansen, Charles (2000). Hansen Solubility Parameters: A user's handbook. Boca Raton, Fla: CRC Press. ISBN 0-8493-1525-5.
