Polyvinylidene Fluoride/Siloxane Nanofibrous Membranes for Long‐Term Continuous CO₂‐Capture with Large Absorption‐Flux Enhancement

Abstract

In a CO2 membrane contactor system, CO2 passes through a hydrophobic porous membrane in the gas phase to contact the amine absorbent in the liquid phase. Consequently, additional CO2 gas is absorbed by amine absorbents. This study examines highly porous polyvinylidene fluoride (PVDF)/siloxane nanofibrous layers that are modified with hydrophobic fluoroalkylsilane (FAS) functional groups and successfully coated onto a macroporous Al2 O3 membrane. The performance of these materials in a membrane contactor system for CO2 absorption is also investigated. Compared with pristine PVDF nanofibrous membranes, the PVDF/siloxane nanofibrous membranes exhibit greater solvent resistance and mechanical strength, making them more suitable for use in CO2 capture by the membrane contactor. The PVDF/siloxane nanofibrous layer in highly porous FAS-modified membranes can prevent the wetting of the membrane by the amine absorbent; this extends the periods of continuous CO2 absorption and results in a high CO2 absorption flux with a minimum of 500 % enhancement over that of the uncoated membranes. This study suggests the potential use of an FAS-modified PVDF/siloxane nanofibrous membrane in a membrane contactor system for CO2 absorption. The resulting hydrophobic membrane contactor also demonstrates the potential for large-scale CO2 absorption during post-combustion processes in power plants.

Hydrophobic fluorocarbon-modified silica aerogel tubular membranes with excellent CO2 recovery ability in membrane contactors

“…However, these polymeric membranes are easily swelled by the aqueous amine solution to change their surface morphology and roughness, leading to a decrease in the CO 2 absorption capacity. To solve the swelling problem of the polymeric membranes, inorganic SiO 2 materials were successfully incorporated into PVDF nanofibrous membranes to form composite PVDF/SiO 2 nanofibrous membranes in our previous study [10]. The as-prepared PVDF/SiO 2 nanofibrous membranes can prevent the wetting of the membrane by aqueous amine solution and can continuously absorb CO 2 for at least four days; this finding indicates that the as-prepared composite PVDF/SiO 2 nanofibrous membranes are durable.…”

Increasing the Performance of Vacuum Membrane Distillation Using Micro-Structured Hydrophobic Aluminum Hollow Fiber Membranes

“…The hydrophilic nature of inorganic ceramic membranes also renders them inapplicable to membrane contactors. Inorganic ceramic membranes have potential in this area because of their outstanding thermal and chemical resistance and high mechanical strength [15][16][17][18][19]. The production of a hydrophobic, porous ceramic membrane is key to its success.…”

Reusable fluorocarbon-modified electrospun PDMS/PVDF nanofibrous membranes with excellent CO 2 absorption performance

“…10. The CO 2 absorption flux of the FAS-modified PDMS/PVDF nanofibrous membranes was able to be continuously maintained at a stable value over 300 min, at approximately 1.5 mmol/m 2 s, for at least four days, which is higher than the CO 2 absorption fluxes reported for other membranes such as polypropylene (PP) (1.0 mmol/m 2 s) [26], polyvinylidene fluoride (PVDF) (1.2 mmol/m 2 s) [27], polytetrafluoroethylene (PTFE) (1.0 mmol/m 2 s) [30], SiO 2 aerogel (0.8-1.2 mmol/m 2 s) [24,25,31] and PVDF/SiO 2 nanofibrous membranes (1.2 mmol/ m 2 s) [44]. Furthermore, the reusability of the PDMS/PVDF membranes submitted to four FAS modifications is also illustrated by the results of three one-day cycles shown in Fig.…”