Highly Permeable Graphene Oxide/Polyelectrolytes Hybrid Thin Films for Enhanced CO2/N2 Separation Performance

Abstract

Separation of CO2 from other gasses offers environmental benefits since CO2 gas is the main contributor to global warming. Recently, graphene oxide (GO) based gas separation membranes are of interest due to their selective barrier properties. However, maintaining selectivity without sacrificing permeance is still challenging. Herein, we described the preparation and characterization of nanoscale GO membranes for CO2 separation with both high selectivity and permeance. The internal structure and thickness of the GO membranes were controlled by layer-by-layer (LbL) self-assembly. Polyelectrolyte layers are used as the supporting matrix and for facilitating CO2 transport. Enhanced gas separation was achieved by adjusting pH of the GO solutions and by varying the number of GO layers to provide a pathway for CO2 molecules. Separation performance strongly depends on the number of GO bilayers. The surfaces of the multilayered GO and polyelectrolyte films are characterized by atomic force microscopy and scanning electron microscopy. The (poly (diallyldimethylammonium chloride) (PDAC)/polystyrene sulfonate (PSS)) (GO/GO) multilayer membranes show a maximum CO2/N2 selectivity of 15.3 and a CO2 permeance of 1175.0 GPU. LbL-assembled GO membranes are shown to be effective candidates for CO2 separation based on their excellent CO2/N2 separation performance.

Layer-by-Layer Assembly of Two-Dimensional Materials: Meticulous Control on the Nanoscale

“…LbL is an excellent way to fabricate membranes or improve existing membranes due to the uniform nature of the conformal coating that can be achieved and the ability to modify the surface exactly as desired ( Figure 2D). GO in its pristine form performs well as a component in an LbL-assembled separation membrane for CO 2 and N 2 , as reported by Heo et al 83 Their LbL-GO composite was assembled as a spraycoated PDAC/PSS multilayer, followed by a positive-GO/negative-GO multilayer. The GO layers essentially functioned as a molecular sieve as a result of the complex molecular pathway for the gas molecules around the flakes.…”

Combining Silk Sericin and Surface Micropatterns in Bacterial Cellulose Dressings to Control Fibrosis and Enhance Wound Healing

“…7b. Hong's group 89 described similar study where polyelectrolyte-supported wellordered GO membranes are developed. A spray-assisted layerby-layer method and pH adjustment is used for precisely controlling the thickness of GO sheets.…”

Top-Down Polyelectrolytes for Membrane-Based Post-Combustion CO2 Capture

“…The LbL assembly success is strongly dependent on the conditions of the aqueous PE solutions (i.e., ionic strength, pH, concentration), substrate (i.e., surface charge, anchors number, surface roughness), and surrounding (i.e., temperature, humidity) [103,107]. Nevertheless, LbL PE film application finds broad research interest in the CO 2 separation from flue gases as advanced separation is expected [99][100][101]108].…”