An interlamellar arrangement of two monolayers of alkylammonium cations [each monolayer has a C-C-C plane of the alkyl chain parallel to the (001) plane of the silicate 2:1 layers] between 2:1 layers of a phyllosilicate. The positively charged end groups (e.g., –NH4+) of the alkylammonium cations are attached to the interlayer silicate surfaces to produce a characteristic d value depending on the identity of the alkylammonium cation.
Cf., alkylammonium layer charge method, alkylammonium organoclay, bilayer, monolayer, organoclay