Effects of Spinning Temperature on the Morphology and Performance of Poly(ether sulfone) Gas Separation Hollow Fiber Membranes

Abstract

In this study, we demonstrated that poly(ether sulfone) (PES) hollow fiber membranes with almost defect-free surfaces could be prepared at low PES concentrations if the hollow fibers were spun at low temperatures by dry-jet wet spinning. A series of hollow fiber membranes were spun at different coagulation batch temperatures (Tc) and dope solution temperatures (Td). Effects of Tc and Td on the membranes’ morphologies and gas separation performances were investigated. Membrane morphologies characterized by using a scanning electron microscope (SEM) showed that the skin layer thicknesses increased with the decreases in Tc and Td. Moreover, mean surface pore sizes of the membranes, which were evaluated by using the gas permeation method, significantly decreased as Tc or Td decreased. PES hollow fiber membranes spun at the lowest temperatures (Tc = 7 °C, Td = 3 °C) showed O2 and CO2 permeances of 18.9 and 53.5 GPU, respectively. And selectivities of O2/N2, CO2/N2, and CO2/CH4 gas pairs were 1.15, 3.26, and 1....