Cobalt-organovermiculite arrangement and mechanical properties: models and experiments

Abstract

The layered structure of the clay mineral, vermiculite, was organophilized with amine molecules and ammonium cations. Enrichment with cobalt was obtained using intercalative process in aqueous environment for ammonium cations and melting-milling intercalation for amine. Each of Co-organovermiculites represents different type of arrangement in clays gallery as revealed by molecular models. Cations Co2+ are partly immersed in to silicate layer and aliphatic chains of ammonium cations are repelled form place of metal cation interaction. Amine in organovermiculite is arranged as lateral double-layer molecules and cobalt atom is positioned in random place in the gallery. Based on the modeled data the properties and mechanical parameters of both Co- organovermiculites was established. Very high compressibility value (82.5 TPa–1) of CoHDTMA-VMT results from the paraffin-like arrangement in the clay gallery and low density 1.25 g · cm–3. CoDDA-VMT low compressibility (3.5 TPa –1) because it is closely packed system with inorganic and organic species in vermiculite interlayer; density is higher 2.031 g · cm–3. Bulk and shear modulus are smaller for CoHDTMA-VMT.