Porous polyetherimide (PEI) and polyethersullone (PES) hollow fiber membranes were spun under the same spinning conditions and the fabricated membranes were characterized using various analytical methods. The membranes were then subjected to gas-liquid contactor experiments. While the PEI casing solution was thermodynamically less stable, the PES casting solution was less viscous which resulted in a more porous membrane structure. The mean pore size and effective surface porosity obtained by the gas permeation test showed superior properties of the PES membrane. Both PEI and PES membranes had sufficiently high LEPw values even though both polymers were known to be relatively hydrophilic, most likely clue to their small pore sizes. The absorption flux of the PES membrane was 4.4 x 10(-3) mol m(-2) s(-1) at the liquid flow velocity V-liquid of 1.8 m s(-1), which was 267% higher than that of the PEI membrane 1.2 x 10(-3) mol m(-2) s(-1)) clue to the larger pore size and smaller tortuosity of the PES membrane. (C) 2014 Elsevier B.V. All rights reserved.