Hygroscopy is the phenomenon of attracting and retaining water molecules from the external atmosphere, which is usually at normal or room temperature, by absorption or adsorption. Adsorbing substances may be physically modified if water molecules become suspended within the substance’s molecules, such as changing volume, boiling point, or any other physical feature or property of the material.
Example of a hygroscopic substance
- Quicklime (calcium oxide) (CaO) is a hygroscopic substance.
- Nylon, ABS, polycarbonate, cellulose are few examples of hygroscopic engineering polymers.