关键词: 蒙脱土, 部分层无序, 结构模型, 锆

Abstract: The structure of pillared montmorillonite is the partially disordered layer lattice.Its basal spacings can be expanded to many possible values with different probabilities depending on the type and structure of the pillars.If a formula describing the X-ray diffraction intensity of partially disordered layer lattice as a function of basal spacings and the corresponding probabilities is computationally simulated with the experimental XRDpattern, the basal spacings and probabilities can thus be obtained.In this paper, zirconium pillared montmorillonite samples were prepared.The simulated results show that the basal spacings are expanded to 2.55 nm, 2.10 nm and 1.26 nm with probabilities of 35%, 2.7% and 38% corresponding to [Zr₄(OH)₈(H₂O)₁₆]⁸⁺, [Zr₃(OH)₄(H₂O)₅]⁸⁺ ions together with some adsorbed water molecules and H₂Oas the main pillaring species in the interlamellar regions, respectively.The experimental results obtained from CBC, ICPetc.are applied to calculating the distribution of the pillars in the interlayer zone.The fashion of the connection between pillars and unite layers is also given.Subsequently, a three-dimensional statistical structural model is built up.The agreement of the pore-volume between the theoretical calculation and experimental result verifies the rationality of the structural model.Therefore, the basal spacing characterized by d001 which is calculated from Bragg e-quation is not exact actually.

Key words: Montmorillonite, Partially disordered layer lattice, Structural model, Zirconium