Microporous zirconia-pillared clays derived from three kinds of zirconium polynuclear ionic species

Abstract

Depending on the degree of polymerization of the zirconium species in zirconium oxychloride solutions, three kinds of microporous clay intercalation compounds have been prepared by cation exchange of a swelling clay with the zirconium polynuclear ionic species. These are products with 7-, 12-, and 14-Á interlayer spacings (=gallery heights). The major species in zirconium oxychloride solutions at room temperature is the zirconium tetramer, [ 4(0 )8+ ( 20) 6-](8" )+, giving the intercalation compound with a 7-A interlayer spacing. Upon hydrolytic polymerization of the zirconium tetramer in solution, the more highly polymerized zirconium species are generated that can provide the intercalation compounds with 12or 14-Á interlayer spacings; the concentration of halogen ions in the solutions governs the kinds of the intercalates. The two polymeric species forming the intercalates with 12-and 14-Á interlayer spacings are composed of three-dimensionally polymerized clusters based upon the tetramer. Examination of the intercalation compounds sheds light on the structure of the ionic species in solution.

Molecular Engineered Porous Nanocomposites of Metal Oxide and Clay Using Surfactants

“…A certain amount of a polyethylene oxide (PEO) surfactants of small molecular weights, with a general chemical formula CI 2 .1 4 H25-29 0(CH 2 CH 2 0)oH (n = [5][6][7][8][9][10][11][12], was added into the laponite dispersion which then became opaque. The suspension was stirred for 2 hours to allow sufficient mixing.…”

“…The development of pillared layered clays has provided very useful knowledge on the precursor solutions [ 1]. The structures of various oligomers in precursor solutions have been comprehensively studied [6,7]. In many eases, the pillaring solutions for the synthesis of pillared layered clays can be used for the synthesis of nanoconiposites.…”

Separation and preconcentration trace amounts of gold by using modified organo nanoclay closite 15A

“…These materials have a two-dimensional pore size larger than conventional zeolites and exhibit specific properties depending on the nature of the pillar. 17 These materials are usually prepared by ion-exchanging cations in the interlayer region of swelling clays with bulky alkylammonium ions, polynuclear complex ions bearing inorganic ligands (hydroxo ligand, chloro ligand), large metal complex ions bearing organic ligands, etc.…”

Preparation of novel porous solids from alumina-pillared fluorine micas by acid-treatment

“…Oxide-pillared fluorine micas [1][2][3][4][5][6][7][8] are obtained from swellable fluorine micas [9][10][11][12] as host crystals, in the same way as from natural clay minerals. The swellable micas show such features as high crystallinity, large cation exchange capacity and high thermal durability.…”