title: Delamination behavior of silicate layers by adsorption of cationic surfactants.
abstract: Smectite that has reacted for 48 h with hexadecyltrimethylammonium (HDTMA) cations equivalent to 0.01-3.0 times the cation exchange capacity (CEC) converts to HDTMA-smectite. The microstructure of this organoclay is observed using X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). When Na cations in the interlayer of clay are exchanged with HDTMA ions, the changes in internal and external surface configuration are augmented by the intercalation of organic surfactants, showing a heterogeneous increase of interlayer spacings. As HDTMA loading increases, the chance of delaminated layers being developed increases locally in the low-charge interlayer regions by the sufficient adsorption of organic surfactants beyond the CEC due to the tendency of alkyl chain interaction.
authors.affiliation: School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-742, Korea. lsyblue@hanmir.com
authors.forename: Seung Yeop
authors.initials: SY
authors.lastname: Lee
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D010316:Particle Size; D017640:Silicates / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D002412:Cations; D002593:Cetrimonium Compounds; D017640:Silicates; D013501:Surface-Active Agents; D001546:Bentonite; D000077286:Cetrimonium