Abstract: Layered silicate materials and applications are disclosed. In one aspect, the invention features layered silicate materials having pores that run generally perpendicular to the layers. In another aspect, the invention features composite materials including layered framework materials (e.g., layered silicate materials, layered Aluminophosphate materials, layered tin sulfides) having pores or openings that run generally perpendicular to the layers.

Abstract: In certain aspects, the invention features methods for forming crystalline membranes (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals. The rate of growth of the seed crystals in the plane of the substrate is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains of uniform crystallographic orientation that extend through the depth of the layer.

Abstract: Layered silicate materials and applications are disclosed. In one aspect, the invention features layered silicate materials having pores that run generally perpendicular to the layers. In another aspect, the invention features composite materials including layered framework materials (e.g., layered silicate materials, layered Aluminophosphate materials, layered tin sulfides) having pores or openings that run generally perpendicular to the layers.

Abstract: Methods of forming permselective oxide membranes that are highly selective to permeation of hydrogen by chemical deposition of reactants in the pore of porous tubes, such as Vycor.TM. glass or Al.sub.2 O.sub.3 tubes. The porous tubes have pores extending through the tube wall. The process involves forming a stream containing a first reactant of the formula RX.sub.n, wherein R is silicon, titanium, boron or aluminum, X is chlorine, bromine or iodine, and n is a number which is equal to the valence of R; and forming another stream containing water vapor as the second reactant. Both of the reactant streams are passed along either the outside or the inside surface of a porous tube and the streams react in the pores of the porous tube to form a nonporous layer of R-oxide in the pores. The membranes are formed by the hydrolysis of the respective halides. In another embodiment, the first reactant stream contains a first reactant having the formula SiH.sub.n Cl.sub.