Performance of Silicon Rubber Coated Hollow Fiber Membrane Contactor for CO2 Gas Absorption

This study focuses on the effect of a silicon rubber coating technique on the hollow fiber membrane contactor for the purpose of CO2 removal. The polymer and the coating agent used were polyetherimide (PEI) and polydimethylsiloxane (PDMS) respectively. The hollow fibers were fabricated via a simple wet spinning technique. The surfaces of the hollow fibers were coated by means of PDMS dissolved in n-hexane applying different protocols. The membranes were characterized applying: gas permeation test (GPT) via pure helium, critical entry pressure of water (CEPw), contact angle and Gas absorption test. Based on the observations, the coating technique resulted in drastic changes in the contact angle and CEPw of the coated membranes for the inside and outside coated hollow fiber membranes in common. Disregarding the method of coating and even the polymer concentration, the contact angle have enhanced dramatically. A slight decrease in CO2 absorption flux for the other cases was outweighed by substantial enhancement in the membrane wetting resistant due to high contact angle and CEPw. This observations showed the high influence of the silicon rubber layer on the CO2 gas absorption, which emphasis the role of this key-parameter in controlling the final membrane contactor performance