A zeolite membrane complex includes a support and a zeolite membrane formed on the support. The zeolite membrane is of an SAT-type zeolite. Among particles on the surface of the zeolite membrane, particles that have aspect ratios higher than or equal to 1.2 and lower than or equal to 10 account for 85% or more of the area of the surface of the zeolite membrane. This improves the orientations of the particles and also reduces the interstices among the particles. As a result, the denseness of the zeolite membrane is improved. Accordingly, for example, high gas separation performance can be obtained when the zeolite membrane complex is used as a gas separation membrane.

Disclosed are a heterogeneous zeolite membrane and a method of preparing the same, and more particularly a heterogeneous zeolite membrane that has CHA and DDR zeolite structures by growing seed particles into a crystal structure different from that of the zeolite membrane and can thus separate CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 even under wet conditions, a method of preparing the same, and a method of capturing and removing carbon dioxide using the membrane.

A zeolite synthesis sol includes particles of an aluminum source with a mean particle diameter of 5 to 500 nm, and a solvent in which the particles are dispersed, the solvent being water that contains a phosphorus source, a structure-directing agent, and a carboxylic acid.

The invention relates to a method for preparing a MeAPO-18 supported membrane comprising a MeAPO-18 crystal layer on a porous support, wherein the obtained MeAPO-18 supported membrane as a lamellar crystal morphology. The invention is also directed to the said membranes and to their use.

A method for producing a crystalline film comprising zeolite and/or zeolite-like crystals on a porous substrate is described. The method has the steps of: providing a porous support; modifying at least a surface of the top-layer of said porous support by treatment with a composition having one or more cationic polymer(s); rendering at least the outer surface of said porous support hydrophobic by treatment with a composition having one or more hydrophobic agent(s); subjecting said treated porous support to a composition having zeolite and/or zeolite-like crystals thereby depositing and attaching zeolite and/or zeolite-like crystals on said treated porous support, and growing a crystalline film of zeolite and/or zeolite-like crystals on said treated porous support and calcination. Crystalline films find use in a variety of fields such as in the production of membranes, catalysts etc.

A zeolite membrane structure includes a porous support, and a zeolite membrane. The zeolite membrane has a first zeolite layer located in a surface of the porous support, and a second zeolite layer located outside of the surface of the porous support and integrally formed with the first zeolite layer. The porous support has an outermost layer in which the first zeolite layer is located. An average thickness of the first zeolite layer is less than or equal to 5.4 micrometers. A porosity of the outermost layer is greater than or equal to 20% and less than or equal to 60%.

Disclosed are a CHA zeolite membrane and a method of preparing the same, and more particularly, a CHA zeolite membrane having high capacity to separate CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 even under wet conditions using a membrane produced using a synthetic precursor having a controlled ratio of Si and Al, a method of preparing the same, and a method of capturing and removing carbon dioxide using the membrane.

The present invention relates to a method of preparing a perm-selective porous membrane and a method of separating gases using the prepared porous membrane. According to the present invention, a membrane is synthesized using a hierarchically structured alumina porous support by a counter diffusion method. During this synthesis, the diffusion rate of metal ions loaded on the porous support is controlled by controlling the pore size of the porous support, and the position at which the membrane is synthesized is controlled by synthesizing the membrane inside the support. This can increase the physical stability of the membrane and make the membrane thicker so as to ensure higher H.sub.2/CO.sub.2 separation factors.

A zeolite membrane complex comprises: a support; and a zeolite membrane formed on the support. The membrane is of SAT-type zeolite, and in an X-ray diffraction pattern obtained by X-ray irradiation to the zeolite membrane, a peak intensity around 2=13.9 is 1.5 times or more a peak intensity around 2=8.5.

A zeolite membrane structure includes a porous support, and a zeolite membrane. The zeolite membrane has a first zeolite layer located in a surface of the porous support, and a second zeolite layer located outside of the surface of the porous support and integrally formed with the first zeolite layer. The porous support has an outermost layer in which the first zeolite layer is located. An average thickness of the first zeolite layer is less than or equal to 5.4 micrometers. An average pore diameter of the outermost layer is greater than or equal to 0.050 micrometers and less than or equal to 0.150 micrometers.