A microporous membrane is made by a dry-stretch process and has substantially round shaped pores and a ratio of machine direction tensile strength to transverse direction tensile strength in the range of 0.5 to 5.0. The method of making the foregoing microporous membrane includes the steps of: extruding a polymer into a nonporous precursor, and biaxially stretching the nonporous precursor, the biaxial stretching including a machine direction stretching and a transverse direction stretching, the transverse direction stretching including a simultaneous controlled machine direction relax.

A microporous membrane is made by a dry-stretch process and has substantially round shaped pores and a ratio of machine direction tensile strength to transverse direction tensile strength in the range of 0.5 to 5.0. The method of making the foregoing microporous membrane includes the steps of: extruding a polymer into a nonporous precursor, and biaxially stretching the nonporous precursor, the biaxial stretching including a machine direction stretching and a transverse direction stretching, the transverse direction stretching including a simultaneous controlled machine direction relax.

A hollow fiber membrane bundle with a longitudinal extent, with a membrane bundle cross section and with a first and a second bundle end, comprising a multitude of hollow fiber membranes extending between the first and the second bundle end, and also comprising, within the membrane bundle cross section, a proportion of threads which are arranged between the hollow fiber membranes and which keep the hollow fiber membranes apart. The arrangement of the threads between the hollow fiber membranes is such that at the first bundle end and/or at the second bundle end the hollow fiber membranes protrude beyond at least some of the threads, such that the hollow fiber membrane bundle has a smaller proportion of threads in a first and/or second end region, extending from the first and/or the second bundle end, than in a bundle region, located between the first and the second bundle end, which has a maximal proportion of threads, the length of the first end region and/or the length of the second end region being 1% to 45% of the bundle length.

A membrane module with a cylindrical housing with a longitudinal extent and with a first and a second housing end, and with a housing shell extending between the first and the second housing end, and also with a housing inner wall, where a hollow fiber membrane bundle of the above type is arranged in the housing oriented in the direction of the longitudinal extent of the housing.

A virus removal membrane includes cellulose, and a primary-side surface through which the protein-containing solution is to be applied and a secondary-side surface from which a permeate that has permeated the virus removal membrane is to be flowed, wherein a bubble point is 0.5 MPa or more and 1.0 MPa or less; and when a solution containing gold colloids having a diameter of 30 nm is applied through the primary-side surface to the virus removal membrane to allow the virus removal membrane to capture the gold colloids for measurement of brightness in a cross section of the virus removal membrane, a value obtained by dividing a standard deviation of a value of an area of a spectrum of variation in the brightness by an average of the value of the area of the spectrum of variation in the brightness is 0.01 or more and 0.30 or less.

A microporous polymeric composition including a matrix polymer having a fractional free volume of at least 0.1 and dispersed particles having a hypercrosslinked polymer.

M(SiF.sub.6)(pyz).sub.3 (M=Cu, Zn, Co, or Ni) has a pore size between a size of H.sub.2 and a size of CO.sub.2, and thus exhibits prominent screening performance for H.sub.2/CO.sub.2. A strong interaction between Cu(SiF.sub.6)(bpy).sub.2 and a CO.sub.2 molecule can hinder the transport of the CO.sub.2 molecule. The above two MOFs both can achieve the H.sub.2/CO.sub.2 separation. By preparing a dense MSiF.sub.6/polymer layer, MSiF.sub.6 is uniformly dispersed in the polymer and is fixed, and subsequently, MSiF.sub.6 is converted into M(SiF.sub.6)(pyz).sub.3 or Cu(SiF.sub.6)(bpy).sub.2 by interacting with an organic ligand. Through vapor-induced in-situ conversion, MOF particles can be well dispersed without interface defects between the MOF particles and the polymer. Even at a doping amount of 80%, the mechanical flexibility and stability of the MMM can still be retained.

Provided are a high temperature-resistant composite nanofiltration membrane and a preparation method thereof. The high temperature-resistant composite nanofiltration membrane includes a base membrane and a polyamide membrane arranged on the base membrane; wherein the polyamide membrane is prepared from raw materials comprising: an amine, an inorganic salt, a silane additive, a polyacyl chloride, and an oil phase solvent; and the silane additive is at least one selected from the group consisting of 3-aminopropyltriethoxysilane, divinyltriaminopropyltrimethoxysilane, N-cyclohexyl-?-aminopropyltrimethoxysilane, and trimethoxy[3-(phenylamino)propyl]silane.

A method for synthesizing a supported molecular sieve membrane by microwaves includes the steps of aging, heating and synthesizing. The aging step is to make a support in contact with a synthetic liquid at 25 C. to 70 C. for 10 hours to 24 hours; the heating step is to raise a temperature of an aged system from an aging temperature to a synthesis temperature within 1 minute to 10 minutes; and the synthesizing step is to synthesize at 80 C. to 120 C. for 2 minutes to 15 minutes. The steps of heating and synthesizing are powered by microwaves.

Provided is a method for preparing a defect-free DDR molecular sieve membrane. Sigma-1 molecular sieve is used as an inducing seed crystal to prepare and obtain a continuous and compact DDR molecular sieve membrane on the surface of a porous ceramic support. An ozone atmosphere or an external field assisted technology is used to remove a template in the pores of the molecular sieve membrane at a low temperature. The invention avoids the formation of intercrystal defects and cracks, an activated DDR molecular sieve membrane has a good selectivity for separating CO2, and the membrane preparation time is significantly reduced.

A zeolite membrane and a preparation method thereof are provided. The method includes: adding an organic binder solution dropwise to zeolite, and thoroughly grinding and stirring; blade-coating a resulting mixture on a substrate at a given thickness; and drying to obtain the zeolite membrane. The preparation of a zeolite membrane does not require a complicated hydrothermal crystal growth process, and the membrane can be prepared directly from natural zeolite or artificial zeolite. A prepared zeolite membrane has the characteristics of simple preparation process, low cost, prominent water permeability, high contaminant rejection rate and high zeolite load. The zeolite membrane, when used for the rejection of contaminants in water, can not only remove macromolecular contaminants in water, but also efficiently remove ammonia nitrogen by way of ion exchange, which is suitable for advanced treatment of wastewater.