Preparation method of asymmetric hollow fiber membrane

Abstract

The invention provides a preparation method of an asymmetric hollow fiber membrane, which comprises the following steps: preparing a membrane casting solution, and extruding the membrane casting solution into a molded product through a die head, performing split-phase curing on the molded product, and performing quenching treatment to obtain a green film; then extracting a solvent system in the green film by using an extracting solution at the extraction temperature of 40-80 DEG C and the concentration of the extracting solution in the extraction process is not lower than 90%, so that the solvent system can be removed from the green film only by 1-4 hours; performing low-temperature drying and high-temperature shaping on the original membrane to obtain a hollow fiber membrane; according to the method, in the process of preparing the hollow fiber membrane, the extraction time can be shortened, and the extraction quality can be ensured, so that a solvent system can be completely removed from membrane filaments by the extract liquor within a relatively short time, and the economic benefit is ensured; meanwhile, it can be guaranteed that the finally prepared hollow fiber membrane has long plasma permeation time, and the plasma permeation time is at least 48 h; and the membrane also has high gas mass transfer rate and large mechanical properties, and is especially suitable for being used as a blood oxygenation membrane.

Description

technical field [0001] The invention relates to the technical field of membrane materials, in particular to a preparation method of an asymmetric hollow fiber membrane. Background technique [0002] In many applications in the fields of chemistry, biochemistry or medicine, there is the problem of separating gaseous components from liquids or adding these components to liquids. For these gas exchange processes, membranes are increasingly used as separation membranes between various liquids and fluids that adsorb or release gaseous components from which gaseous components are separated or added. The fluid here can be a gas or a liquid containing or adsorbing the gas components to be exchanged. Using such membranes, an exchange surface can be provided for gas exchange and, if necessary, direct contact between liquid and fluid can be avoided. [0003] An important application of membrane-based gas exchange methods in the medical field is oxygenators, also called artificial lun...

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Problems solved by technology

[0004] Most of the hollow fiber membranes currently used in oxygenators are asymmetric membranes, which include a separation layer and a support layer, wherein the support layer is located on the side of the hollow fiber membrane close to the inner cavity, and the separation layer is located on the side of the hollow fiber membrane away from the inner cavity ; The support layer has a high porosity, thereby ensuring that oxygen and carbon dioxide can pass through the hollow fiber membrane relatively freely, that is, the CO of the hollow fiber membrane 2 Mass transfer rate and O 2 The mass transfer rate is high; and the separation layer is a dense layer, that is, there are no holes on the surface and inside of the separation layer, which ensures that the hollow fiber membrane has a long plasma permeation time and a long service life; but in the preparation of the above hollow fiber membrane In the process, in order to remove the solvent system in the quenched membrane filament as much as possible, the R&D personnel often take a long extraction time, generally 12-24 hours, and the extraction time cost is too large, thus reducing the economic benefit; how to shorten the extraction time time, but also to ensure the quality of the extraction, so that the extract can completely remove the solvent system from the membrane filaments in a short period of time; Fibrous Membrane Development

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