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.

Provided is a method for manufacturing a porous body by which a porous body having a plurality of layers different from each other in pore diameter can be manufactured more easily than before. The method includes heating a raw material solution including a metal ion and an organic ligand to synthesize an interpenetrated metal-organic framework layer; and after synthesizing the interpenetrated metal-organic framework layer, synthesizing a non-interpenetrated metal-organic framework layer under conditions in which concentrations of the metal ion and the organic ligand in the raw material solution and/or a heat temperature are lower than that in synthesizing the interpenetrated metal-organic framework, to obtain a porous body including the interpenetrated metal-organic framework layer and the non-interpenetrated metal-organic framework layer stacked together.

Provided are an all-silica zeolite separation membrane for separating carbon dioxide, etc., and not causing a decrease in the processing amount due to adsorption of water molecules, and a production method therefor. One aspect of the present invention is a zeolite separation membrane, in which the framework of a zeolite crystal structure formed on a porous support is all silica, characterized in that the zeolite crystal structure formed on the porous support is fluorine free. Another aspect of the present invention is a method for producing a zeolite separation membrane having a zeolite crystal structure on a porous support, characterized in that the method includes a step of producing a seed crystal, a step of applying the seed crystal onto the porous support, a step of producing a membrane synthesis raw material composition, and a step of immersing the porous support having the seed crystal applied thereon in the membrane synthesis raw material composition and performing hydrothermal synthesis, and the membrane synthesis raw material composition contains a silica source and an organic template and does not contain a fluorine compound.

A dehydration method is a dehydration method for selectively separating water from a mixture that contains water, using a zeolite membrane having an AFX structure, and the method includes a step of supplying the mixture to a supply side space of the zeolite membrane having an AFX structure, and a step of making a pressure difference between the supply side space and a permeation side space of the zeolite membrane having an AFX structure.

A separation membrane structure comprises a porous support body, a zeolite membrane formed on the porous support body and comprising pores having a major diameter and a minor diameter. The ratio of a major diameter to a minor diameter is greater than 1.0. The minor diameter is greater than or equal to 0.30 nm and less than or equal to 0.35 nm.

The present invention provides a method for fabricating an oriented zeolite film including preparing a metal substrate and zeolite crystal with an aspect ratio of at least 2; laying the zeolite crystal on the metal substrate to obtain a first metal substrate; applying a precursor solution containing a first structure directing agent and a solvent on the first metal substrate to obtain a second metal substrate; placing the second metal substrate in a sealed container containing a predetermined amount of the solvent; and heating the sealed container at 100-550° C. for at least 15 minutes. Thus, a continuous oriented zeolite film is formed with uniform thickness and improved anti-corrosion ability.

A zeolite membrane complex includes a porous support and a zeolite membrane formed on the support. The zeolite membrane contains Al, P, and a tetravalent element. The composition of the zeolite membrane measured by X-ray photoelectron spectroscopy is such that the molar ratio of the tetravalent element to Al is higher than or equal to 0.01 and lower than or equal to 0.5, the molar ratio of P to Al is higher than or equal to 0.5 and lower than 1.0, and the total molar ratio of P and the tetravalent element to Al is higher than or equal to 0.9 and lower than or equal to 1.3. The zeolite membrane contains a zeolite crystal with an accessible volume higher than or equal to 450 Å.sup.3.

Provided herein are methods for making a freeze-cast material having a internal structure, the methods comprising steps of: determining the internal structure of the material, the internal structure having a plurality of pores, wherein: each of the plurality of pores has directionality; and the step of determining comprises: selecting a temperature gradient and a freezing front velocity to obtain the determined internal structure based on the selected temperature gradient and the selected freezing front velocity; directionally freezing a liquid formulation to form a frozen solid, the step of directionally freezing comprising: controlling the temperature gradient and the freezing front velocity to match the selected temperature gradient and the selected freezing front velocity during directionally freezing; wherein the liquid formulation comprises at least one solvent and at least one dispersed species; and subliming the at least one solvent out of the frozen solid to form the material.

A separation membrane structure comprising a porous support, a first glass seal, and a separation membrane. The porous support includes through-holes which connect a first end surface and a second end surface. The first glass seal is configured to cover the first end surface. The separation membrane is formed on an inner surface of the through-holes. The first glass seal has a first seal body part and a first extension part. The first seal body part is disposed on the first end surface. The first extension part is connected to the first seal body part and disposed on the inner surface of the through-holes. The separation membrane has a first connection part connected to the first extension part of the first glass seal. A first thickness of the first connection part is less than or equal to 10 microns, and less than or equal to 3.2 times a center thickness at a longitudinal center of the separation membrane.

A method for manufacturing a zeolite membrane structure includes a step of forming a first zeolite membrane on a porous support by hydrothermal synthesis in a state in which the porous support is immersed in a first zeolite membrane formation solution, a step of immersing the porous support formed the first zeolite membrane for greater than or equal to 5 minutes in a second zeolite membrane formation solution at greater than or equal to 10 degrees C. and less than or equal to 70 degrees C. and greater than or equal to pH 10, and a step of forming a second zeolite membrane on the first zeolite membrane by hydrothermal synthesis in a state in which the porous support formed the first zeolite membrane is immersed in the second zeolite membrane formation solution. The first zeolite membrane and the second zeolite membrane share at least one composite building unit constituting a framework structure.