Process by which a substance becomes transferred into pre-existing spaces of molecular dimensions in a second substance.
The term as defined here is specific to polymer science. An alternative definition of 'intercalation' applies in some other fields of chemistry.
PAC, 2004, 76, 1985. 'Definition of terms related to polymer blends, composites, and multiphase polymeric materials (IUPAC Recommendations 2004)' on page 1991 (https://doi.org/10.1351/pac200476111985)