Reusable fluorocarbon-modified electrospun PDMS/PVDF nanofibrous membranes with excellent CO2 absorption performance

Abstract

One-dimensional (1-D) electrospun nanofibrous membranes are well-established materials because of their low cost, simplicity, ease of scale-up and wide range of applications. In this study, for the first time, porous polydimethylsiloxane (PDMS)/polyvinylidene fluoride (PVDF) nanofibrous membranes featuring hydrophobic fluorocarbon functional group (fluoroalkylsilane, FAS) modifications were successfully prepared using an electrospinning process, and their performance in a membrane contactor for CO2 absorption was investigated. The water contact angle of PDMS/PVDF nanofibrous membranes submitted to four FAS modifications was approximately 150°. The as-prepared superhydrophobic FAS-modified PDMS/PVDF nanofibrous membranes were able to prevent wetting by an amine absorbent, therefore allowing for long periods of continuous CO2 absorption over at least four days, with a CO2 absorption flux of approximately 1.5mmol/m2s. Furthermore, the FAS-modified PDMS/PVDF nanofibrous membranes demonstrated reusability over three one-day cycles. Thus, the as-prepared FAS-modified PDMS/PVDF nanofibrous membranes are not only durable but also reusable, which indicates that the material is also promising for large-scale CO2 absorption during post-combustion process in power plants.