Facile Preparation of Graphene Oxide Membranes for Gas Separation

Abstract

We herein report a facile preparation of graphene oxide (GO) membranes including three steps: (1) mild freeze–thaw exfoliation to get large GO nanosheets, (2) purification of exfoliated GO nanosheets through pH adjustment, and (3) spin coating to fabricate smooth GO membranes with uniformly aligned GO nanosheets. The fabricated GO membranes are subject to single gas permeation tests, with the obtained gas permeance in the order He > H2 ≫ CH4 > CO2 > N2 ≫ SF6, indicating a dominant molecular sieving separation mechanism. The H2/CO2 mixed gas permeation tests reveal H2 permeance up to 3.4 × 10–7 mol/(m2·s·Pa) and a H2/CO2 separation factor up to 240, which are among the best of all the reported membranes for H2/CO2 separation. The separation factor drops to 47 at a higher temperature of 120 °C, but the H2 permeance is further increased to 6.7 × 10–7 mol/(m2·s·Pa), ensuring a higher gas separation throughput under higher temperatures. This study paves the way toward large-scale production and application of GO membranes as promising gas separation materials.

Cation-diffusion controlled formation of thin graphene oxide composite membranes for efficient ethanol dehydration

“…From nano-sized particles (e.g., carbon dots [18]), small molecules (e.g., piperazine [19], surfactant [20,21]) to polymer chains (e.g., polyvinyl alcohol [22]), different chemical species are manipulated to modulate nanostructures and properties of GO-based membranes. With the methodology to functionalize GObased materials, several kinds of membranes for separating specific mixtures [23][24][25][26][27][28][29][30] have been developed. Particularly for liquid separation processes like nanofiltration [31] and pervaporation [32], the structural stability of GO membranes is essential for molecular separation as GO may disintegrate when adsorbing excessive solvent molecules [33,34], and this situation may get worse for the liquid with a high flow rate promoting turbulence across the membrane surface to reduce con-centration polarization.…”

Facile and size-controllable preparation of graphene oxide nanosheets using high shear method and ultrasonic method

“…The layered materials feature strong in-plane chemical bonds but weak interlayer interactions, and can be easily peeled to multiple or even single-layered nanosheets [1]. Recently, there has been growing interest in exfoliation of layered materials to produce two-dimensional (2D) nanosheets, such as graphene [2][3][4][5][6], graphene oxide (GO) [1,[7][8][9][10], etc.…”

“…Recently, there has been growing interest in exfoliation of layered materials to produce two-dimensional (2D) nanosheets, such as graphene [2][3][4][5][6], graphene oxide (GO) [1,[7][8][9][10], etc. GO has recently attracted substantial interest as a possible intermediate for the preparation of graphene [11][12][13] and metal oxide/graphene nanocomposites [14][15][16].…”

“…GO has recently attracted substantial interest as a possible intermediate for the preparation of graphene [11][12][13] and metal oxide/graphene nanocomposites [14][15][16]. It also has been used to prepare a strong paper-like material owing mainly to their interesting electrical, thermal, mechanical and optical properties [1,8,10,[17][18][19][20][21][22]. The small area of GO sheets results in high inter-sheet contact resistance in the films due to a large amount of intersheet junctions [10,23,24].…”

Carbon Nanomaterials Based Membranes

“…Graphene oxide membrane can be prepared by vacuum filtration of GO solution on a template support or spraying of GO solution on solid support by doctor blade and subsequent removing the solid support [16]. Thin and uniformly aligned graphene oxide membrane can be obtained by spin coating [19]. Single layer GO membrane has few limitation for bulk production and uses, such as durability, stability and fragile, hence, difficult to handle [16].…”