| 摘要 |
A method for preparing an epoxysilicone coated asymmetric membrane is disclosed, wherein the method comprises: (a) casting a porous asymmetric membrane layer; (b) drying the porous asymmetric membrane layer to form a dry porous asymmetric membrane; (c) uniformly coating the dry porous asymmetric membrane with a coating comprising a dilute epoxysilicone solution to form a coated membrane; and (d) irradiating and drying the coated membrane to produce the epoxysilicone coated membrane. Preferably, the method comprises coating a porous asymmetric membrane layer with a UV-curable controlled release epoxysilicone coating. A mixture of the epoxysilicone resin and an onium photocatalyst are applied to the porous asymmetric membrane layer in a dilute non-polar solution and cured by UV or electron beam radiation to produce a dry epoxysilicone coated membrane. The porous asymmetric membrane layer is comprised of an asymmetric cellulosic membrane or an asymmetric polymer membrane with a low selectivity. The epoxysilicone coating was found to provide the asymmetric membrane layer with improved selectivity which extends to separation temperatures below 70 degree C and provides stable flux rates. Membranes produced in this manner are useful for the separation of gases such as carbon dioxide from natural gas.
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