The present invention provides a hollow fiber membrane including a cellulose acetate-based polymer, in which when an inner surface of the hollow fiber membrane is observed under an atomic force microscope, a plurality of groove-like recesses oriented in a lengthwise direction of the hollow fiber membrane are observed, an average length of the recesses is greater than or equal to 200 nm and less than or equal to 500 nm, an average width of the recesses is greater than or equal to 15 nm and less than or equal to 50 nm, and an aspect ratio defined as a ratio of the average length to the average width of each of the recesses is greater than or equal to 6 and less than or equal to 22.

The invention relates to a method for preparing a hierarchical porous zeolite membrane and an application thereof, comprising the following steps: a mesoporous structure-directing agent is added to limit the growth of zeolite crystals, and self-assembled in the crystallization process to generate a mesoporous structure. Based on a seed crystal induced secondary nucleation mechanism, this method can realize one-step hydrothermal synthesis of hierarchical porous zeolite membrane with the advantages of mild and controllable synthesis conditions, simple process, good repeatability, reduced energy consumption and cost savings. The hierarchical porous zeolite membrane prepared by the method has good cut-off performance, and the cut-off molecular weight is adjustable between 200 to 500,000 Da.

Described herein is a polyamide hollow fiber membrane and methods of making and using the hollow fiber membrane. The polyamide hollow fiber membrane has an isopropanol permeability of from about 5 L/m2 h bar to about 150 L/m2 h bar and a particle rejection percentage of about 100% for particles having a nominal diameter of from about 1 nm to about 25 nm. The polyamide hollow fiber membranes described herein are particularly useful for photoresist filtration, for example.

A porous membrane has a thickness of 150 m or greater. The pore diameters of a first surface are smaller than the pore diameters of a second surface. The average value of the pore diameters of the first surface is 60 nm or less, and the coefficient of variation of the pore diameters is 10% or greater and 50% or less.

A hollow fiber membrane laminate that includes a plurality of hollow fiber membranes wound to form a plurality of layers in a cylinder shape. The hollow fiber membranes are wound around a central axis while reciprocating a feeding point of the hollow fiber membranes along a central axis. Hollow fiber membranes adjacent to each other in each respective layer are separated by a predetermined separation distance. A speed differential z is reduced for successive layers approaching an outer side of the cylinder to maintain the predetermined separation distance. The speed differential z has a value obtained by dividing a pitch of the hollow fiber membranes within a respective layer by a traverse reciprocating distance.

Disclosed herein are an apparatus for heat-treating an inner side surface of a braid for a hollow fiber membrane reinforcement for a water treatment and a braid for a hollow fiber membrane reinforcement manufactured using the heat-treatment apparatus, wherein a fiber tissue forming an inner side surface of a braid becomes dense, and the inner diameter of the braid can be expanded, and the circularity of the inner and outer diameters can be accurate, and a compressive strength can be increased, whereby the physical property of a reinforcement membrane of a hollow fiber can be enhanced, and a filtration reliability and water penetration can be improved, thus obtaining an increased service life of a product and an economical saving effect.

The present invention pertains to a hollow fiber membrane module (5) for removing gas from an objective liquid or supplying gas to the objective liquid, comprising: a hollow fiber membrane bundle (20); and a collecting member (51) configured to collect first ends (20a) of the hollow fiber membrane bundle (20) while maintaining openings of opened end portions (22a) of hollow fiber membranes (22) of the hollow fiber membrane bundle (20), wherein the collecting member (51) has a coupling portion configured to couple the collecting member (51) to an installation object in a detachable and liquid-tight manner.

Provided is a porous membrane having a high blocking performance suited for filtration application as well as being excellent in water permeability performance, which is capable of providing stable filtering operation over a long period of time. The porous membrane has a cross-sectional pore size index of 40 or more in a region where a membrane thickness position ranges from 0.1 to 0.2 within the membrane thickness which is normalized by defining one surface position as 0 and the other surface position as 1 and divided into ten regions in the membrane thickness direction, the cross-sectional pore size index being calculated by: Cross-Sectional Pore Size Index=(Cross-Sectional Pore Size in the Range)/(Pore Size of the One Surface).

A reverse osmosis membrane (100) and a method of processing the same are described herein. One device includes a hollow fiber membrane material (102), and a polyamide material (104) on a surface of the hollow fiber membrane material(1 02) in a lumen (106) side of the hollow fiber membrane material (102). One method includes forming the hollow fiber membrane material (102), and forming the polyamide material (104) on the surface of the hollow fiber membrane material (102) in the lumen (106) side of the hollow fiber membrane material (102).

A wound care system comprising a single-layer arrangement of mutually parallel capillary membranes with a porous, semi-permeable wall, a lumen and at least one open end. The capillary membranes are connected to one another by connection elements to form a mat and are held at a distance from one another by the connection elements.