# Synthesis and Characterization of PVDF Hollow Fiber Using Adipic Acid as an Additive for Gas–Liquid Membrane Contactor Application

## TL;DR

This paper describes the creation of PVDF hollow fiber membranes using adipic acid, which showed better CO2 capture performance than commercial alternatives.

## Contribution

The use of adipic acid as an additive in PVDF hollow fiber membranes for improved CO2 capture in gas–liquid membrane contactors.

## Key findings

- PVDF hollow fibers with nanopores were observed using HIM, which may prevent membrane wetting.
- PVDF hollow fibers showed higher CO2 flux compared to commercial polypropylene fibers.
- In-house PVDF modules outperformed commercial ones in CO2 removal tests.

## Abstract

In the present work, poly(vinylidene fluoride) (PVDF)
hollow fiber
membranes were obtained using adipic acid as an additive in dope solution.
The PVDF hollow fibers produced were used in the gas–liquid
membrane contactor process, aiming at CO2 capture. The
morphology of PVDF hollow fibers was also characterized by scanning
electron microscopy and helium ion microscopy (HIM). These techniques,
mainly HIM, allowed us to clearly observe the presence of nanopores
at the outer membrane surface, which may favor the process efficiency
by preventing membrane wetting. The hollow fiber membranes were also
characterized by helium picnometry, gas permeation, and the contactor
membrane process. In the performance tests for CO2 removal,
the number of fibers and length of the PVDF hollow fibers were taken
into account, since in-house modules were also compared to commercial
ones. From these experiments, it could be seen that PVDF hollow fibers
exhibited better performance of the CO2 flux than commercial
polypropylene hollow fibers.