ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Study of the octadecylammonium-montmorillonite system

H. Slosiariková, B. Číčel, and J. Hronský

Department of Inorganic Chemistry, Faculty of Natural Sciences, Komenský University, CS-842 15 Bratislava

Abstract: The reaction of octadecylammonium (ODA) with montmorillonite gives successively rise to one-layer (|1|α_II) and two-layer (|2| α_II) complexes with ODA chains oriented parallelly with the surface of layer 2:1 and one-layer (|1|α_⊥) and two-layer (|2| α_⊥) complexes with ODA chains orientated under an angle exceeding 50° with respect to the surface of layer 2:1 . These complexes come into existence in the Na-, Mg-, Ca-, Cu-, Co-, and (Ca, Mg)-forms of montmorillonite. The proceeding reaction exhibits, to a certain extent, both character of ion exchange and ODA sorption in the interlayer space. The |2| α_II → |1|α_⊥  . transitions are at 0.8—1.0 mmol g^-1 ODA for all forms while the  |1|α_⊥→ |2| α_⊥  transitions are to be observed at 1.7—2.0 mmol g^-1 ODA sorbed on the sample. The start of two-layer complex |2| α_⊥  formation is accompanied by an increase in hydrophility of montmorillonite. As for the Cu- and Co-form of montmorillonite, it is supposed that the complexes of octadecylamine with Cu²⁺ and Co²⁺ are formed in the interlayer space. The presence of ODA in the interlayer space brings about changes in bonding within the structure of montmorillonite.

Full paper in Portable Document Format: 405a585.pdf

Chemical Papers 40 (5) 585–594 (1986)