An example material includes a planar layer of MFI zeolite. The planar layer has a thickness in a range between 4 nm and 10 nm for at least 70% of a basal area of the planar layer.

A separation membrane complex includes a porous support and a separation membrane formed on the support. In the separation membrane complex, average CF.sub.4 permeance of one membranous end portion is 5 times or more and 100 times or less of average CF.sub.4 permeance of a membranous central portion, the one membranous end portion being a portion of the separation membrane that is within a range of one-tenth of the longitudinal length of the separation membrane from one longitudinal edge of the separation membrane, the membranous central portion being a portion of the separation membrane excluding the membranous end portions on both longitudinal sides of the separation membrane.

A zeolite membrane composite includes a porous support and a zeolite membrane formed on the support. The zeolite membrane includes a low-density layer that covers the support, and a compact layer that covers the low-density layer. The compact layer has a higher content of a zeolite crystalline phase than the low-density layer. By in this way forming the compact layer on the low-density layer that covers the support, the thin compact layer with no defects can be formed more easily than in the case where a compact layer is formed directly on a support.

A dehydration method is a dehydration method for selectively separating water from a mixture that contains water, and the method includes a step of supplying the mixture to a supply side space of a separation membrane, and a step of making a pressure difference between the supply side space and a permeation side space of the separation membrane. The separation membrane includes a first zeolite membrane that faces the permeation side space and is constituted by a first zeolite and a second zeolite membrane that faces the supply side space and is adjacent to the first zeolite membrane. The second zeolite membrane is constituted by a second zeolite that has the same framework structure as framework of the first zeolite and has a lower Si/Al atom ratio than a Si/Al atom ratio of the first zeolite.

The present disclosure may provide a CHA-DDR type zeolite membrane including: a first layer including a CHA structure and a DDR structure; and a second layer which is provided on the first layer and includes a DDR structure, wherein the CHA-DDR type zeolite membrane is in the form of a film having a thickness of 100 nm to 5 m, including a CHA structure and a DDR structure.

A crystalline material contains oxygen, aluminum and phosphorus, and has powder X-ray diffraction peaks shown below. When the peak at 2=14.170.2 is used as the reference peak and the intensity of the reference peak is set to 100, for example, the relative intensity of the peak at 2=8.650.2 is 1 to 15. The relative intensity of the peak at 2=9.990.2 is 1 to 15. The relative intensity of the peak at 2=16.520.2 is 5 to 80. The relative intensity of the peak at 2=17.370.2 is 1 to 15. The relative intensity of the peak at 2=21.810.2 is 10 to 80.

Systems, devices and methods for molecular separation including a molecular separation device comprising at least a polycrystalline metal-organic framework (MOF) and a nanocrystalline, zeolite MFI, wherein the MOF forms a polycrystalline membrane with zeolite MFI nanoparticles dispersed therein, and the MOF membrane matrix contacting and surrounding the zeolite MFI nanoparticles form a permselective nanoporous structure.

There are provided DDR type zeolite seed crystals capable of inhibiting generation of surplus DDR type zeolite crystals in the case of using the DDR type zeolite seed crystals as seed crystals upon forming a DDR type zeolite membrane on the surface of a porous support. The DDR type zeolite seed crystals have an average particle size of 0.05 to 1.5 ?m; contain 90% or more of particles having an aspect ratio, which is obtained by dividing the maximum Feret's diameter by the minimum Feret's diameter, of 1 to 3; and have not more than 0.3 of a coefficient of variation of the square of the aspect ratio.

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.

The invention discloses a method for the pervaporation and vapor-permeation separation of a gas-liquid mixture or a liquid mixture by a SAPO-34 molecular sieve membrane prepared in a dry gel process, comprising: 1) synthesis of SAPO-34 molecular sieve seeds; 2) coating the SAPO-34 seeds on a porous support; 3) preparation of a mother liquor for dry gel synthesis of SAPO-34 molecular sieve membrane; 4) supporting the mother liquor for dry gel synthesis on the porous support coated with SAPO molecular sieve seeds and drying; 5) placing the porous support prepared in step 4) into a reaction vessel, adding a solvent, performing crystallization of the dry gel; 6) calcining; 7) using the SAPO-34 molecular sieve membrane obtained from step 6) to perform separation of a gas-liquid mixture or a liquid mixture by a process of pervaporation separation or vapor-permeation separation. The invention has the advantages of very high methanol selectivity and permeation flux, lowering synthesis cost of molecular sieve membrane and lowering environment pollution.