Hansenparameters

Hansen parameters, also known as Hansen Solubility Parameters (HSP), are a theoretical model used to predict the solubility of a polymer or other solute in a solvent or mixture of solvents. Developed by Charles Hansen in the 1960s, this model quantifies the intermolecular forces between molecules.

The model proposes that the total cohesive energy density of a substance can be broken down into three components: dispersion forces (δD), polar forces (δP), and hydrogen bonding forces (δH). Each component is represented by a numerical value, and the sum of these three values represents the total Hansen Solubility Parameter (δT). The equation for the total parameter is δT = δD + δP + δH.

For a solute to dissolve in a solvent, their respective Hansen solubility parameters must be similar. Specifically, the difference between the δT values of the solute and the solvent should be small, generally within a certain range (often considered less than 2-3 MPa^0.5). Similarly, the individual component parameters (δD, δP, and δH) should also be relatively close for effective dissolution.

Hansen parameters find widespread application in various industries, including coatings, adhesives, printing inks, and pharmaceuticals. They are used to select appropriate solvents for dissolving polymers, predicting compatibility of materials, and designing new formulations. The prediction is based on the principle that "like dissolves like," where similar intermolecular forces lead to solubility. While a useful predictive tool, it's important to note that Hansen parameters are a simplification and experimental verification is often recommended for critical applications.