A novel surface modified polyvinylidene fluoride hollow fiber membrane contactor for CO2 absorption

Abstract

A novel surface modified polyvinylidene fluoride (PVDF) hollow fiber membrane was fabricated via a dry–wet phased inversion process. A surface modifying macromolecule (SMM) was used as an additive in the spinning dope. During phase inversion SMM migrates to the membrane surface and functions as both a pore former and surface modifier. The surface modified PVDF membrane showed large pore size, higher effective surface porosity, contact angle and porosity but lower critical water entry pressure compared to the PVDF hollow fiber membrane without SMM. The performance of the surface modified membrane in contactor application for CO2 absorption via distilled water as absorbent was studied. The results show that the surface modified PVDF membrane has higher performance compared to control PVDF membranes. With the membrane prepared from SMM in the spinning dope a maximum CO2 flux of 7.7×10−4 mol/m2 s was achieved at 300 ml/min of absorbent flow rate, which was almost 93% more than the other membrane. In a long-term stability study, CO2 flux was decreased only about 7.7% by using surface modified PVDF membrane during 150 h operation.