3D self assembled graphene based cellulose acetate mixed matrix membranes for CO2/CH4 separation: An investigation

Abstract

This study investigates the development of three-dimensional (3D) Self-Assembled Graphene (SAG) and its potential as a filler material in mixed matrix membranes (MMMs) for efficient CO₂ separation. SAG was synthesized via a one-step hydrothermal treatment of graphene oxide (GO). Additionally, reduced graphene oxide (rGO) was synthesized via chemical reduction of GO and tested alongside SAG and GO as filler materials in cellulose acetate (CA) based MMMs. Structural and gas separation properties of SAG, rGO, and GO-based MMMs were compared to identify the superior material for CO₂ separation applications. Model biogas 40 % CO2 and 60 % CH4 is used for gas permeation testing. Characterization techniques such as X-ray Photoelectron Spectroscopy (XPS), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, and X-ray Diffraction (XRD) were employed to evaluate the structural and thermal properties of the fillers and membranes. Gas permeation studies revealed that MMMs containing SAG exhibited superior CO₂ separation performance compared to rGO and GO-based membranes. The 1 % SAG/CA MMMs showed highest CO2 permeability of 50.96 Barrers which is approximately 364 % higher than pure CA membrane, 178 % higher than GO based MMMs, and 133 % higher than rGO based MMMs.