Method for substance separation using a cellulose hydrate membrane in size exclusion chromatography

摘要

There is proposed a separation method for mixtures of materials, using a cellulose hydrate membrane having a porous double structure which consists of micropores having a diameter in the range from >100 nm to 20 μm and ultrapores which have a diameter of <100 nm and which are not accessible to Blue Dextran having an average molecular weight Mw of 2 000 000, wherein the fraction of the volume of the ultrapores is more than 15% of the entire pore volume accessible to water, and wherein, in a preferred embodiment, sulfonic acid ligands are bonded to the membrane.

主权项

1. A method for separating a mixture of materials comprising at least two components of different average molecular weight Mw in a range from 4000 to 4 000 000, comprising the steps:
A) contacting the mixture of materials in a first liquid medium with at least one flat adsorbent and adsorptively depleting the at least one component having a lower average molecular weight from the first liquid medium through the at least one flat adsorbent, and B) separating the at least one flat adsorbent from step A) from the first liquid medium, which comprises the at least one component having a higher average molecular weight,
wherein the at least one flat adsorbent is a membrane having a porous double structure consisting of:micropores having a diameter in the range from >100 nm to 20 μm, andultrapores which have a diameter of <100 nm and which are not accessible to Blue Dextran having an average molecular weight Mw of 2 000 000, and wherein a fraction of the volume of the ultrapores is more than 15% of an entire pore volume accessible to water, and wherein the membrane is obtained by a method comprising:
providing a cellulose ester membrane as a starting material for the membrane; andsequentially hydrolyzing said cellulose ester membrane in a swelling medium and crosslinking said cellulose ester membrane with an at least bifunctional agent, wherein the duration of hydrolysis is in the range of 5 to 45 minutes.