Patent ID: 11883777

Abstract:
Asymmetric hollow fiber membranes, membrane contactors, and related production and use methods. The asymmetric hollow fiber membranes include a porous substrate having a multiplicity of pores, the porous substrate including at least a first semi-crystalline thermoplastic polyolefin copolymer derived by polymerizing at most 3 wt. % of linear or branched alpha olefin monomers with at least 97 wt. % of 4-methyl-1-pentene monomer. The asymmetric hollow fiber membranes also include a skin layer overlaying the porous substrate, the skin layer including a second semi-crystalline thermoplastic polyolefin copolymer derived by polymerizing at least 2 wt. % of linear or branched alpha olefin monomers with at most 98 wt. % of 4-methyl-1-pentene monomer. The skin layer is less porous than the porous substrate and forms an outer surface of the asymmetric hollow fiber membrane, while the porous substrate forms an inner surface of the hollow fiber membrane. The skin layer is preferably nonporous.