Scalable fabrication of deoxygenated graphene oxide nanofiltration membrane by continuous slot-die coating

et al. 2021

Nanomaterials

Self Cite

Graphene oxide (GO) has been a prized material for fabricating separation membranes due to its immense potential and unique chemistry. Despite the academic focus on GO, the adoption of GO membranes in industry remains elusive. One of the challenges at hand for commercializing GO membranes lies with large-scale production techniques. Fortunately, emerging studies have acknowledged this issue, where many have aimed to deliver insights into scalable approaches showing potential to be employed in the commercial domain. The current review highlights eight physical methods for GO membrane fabrication. Based on batch-unit or continuous fabrication, we have further classified the techniques into five small-scale (vacuum filtration, pressure-assisted filtration, spin coating, dip coating, drop-casting) and three large-scale (spray coating, bar/doctor blade coating, slot die coating) approaches. The continuous nature of the large-scale approach implies that the GO membranes prepared by this method are less restricted by the equipment’s dimensions but rather the availability of the material, whereas membranes yielded by small-scale methods are predominately limited by the size of the fabrication device. The current review aims to serve as an initial reference to provide a technical overview of preparing GO membranes. We further aim to shift the focus of the audience towards scalable processes and their prospect, which will facilitate the commercialization of GO membranes.

Section: Large-scale Fabrication Techniquesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fabrication Techniques for Graphene Oxide-Based Molecular Separation Membranes: Towards Industrial Application

Kwon

et al. 2021

Nanomaterials

Self Cite

“…In addition, the GO layer becomes impermeable to both water and gas molecules after chemical reduction 24 . To achieve the barrier properties of stacked GO films, several fabrication methods have been suggested such as spin-coating 25 , spray-coating 26 , vacuum filtration 27 , 28 , bar-coating 29 , 30 , slot-die coating 31 , and layer-by-layer (LBL) assembly 3 , 32 . LBL assembly is particularly effective owing to its numerous advantages; it allows the easy control of the GO coating thickness in the nanometer-scale with highly aligned GO nanosheets, and can be applied to complex geometries with excellent gas barrier performances 32 – 34 .…”

Section: Introductionmentioning

confidence: 99%

Diamine vapor treatment of viscoelastic graphene oxide liquid crystal for gas barrier coating

Kim

et al. 2021

Sci Rep

Self Cite

A layered graphene oxide/ethylenediamine (GO/EDA) composite film was developed by exposing aqueous GO liquid crystal (GOLC) coating to EDA vapor and its effects on the gas barrier performance of GO film were systematically investigated. When a GO/EDA coating with a thickness of approximately 1 μm was applied to a neat polyethylene terephthalate (PET) film, the resultant film was highly impermeable to gas molecules, particularly reducing the gas permeance up to 99.6% for He and 98.5% for H2 in comparison to the neat PET film. The gas barrier properties can be attributed to the long diffusion length through stacked GO nanosheets. The EDA can crosslink oxygen-containing groups of GO, enhancing the mechanical properties of the GO/EDA coating with hardness and elastic modulus values up to 1.14 and 28.7 GPa, respectively. By the synergistic effect of the viscoelastic properties of GOLC and the volatility of EDA, this coating method can be applied to complex geometries and EDA intercalation can be spontaneously achieved through the scaffold of the GOLC.

“…However, utilizing specialized techniques such as electrospinning, nonsolvent-induced phase separation, oxidizing agents, and blending with carbon materials, various nanostructures including nanowires, nanobers, and nanospheres have been generated. [27][28][29][30][31][32] For example, polypyrrole conducting polymer with nanosheets were formed using electrochemical reactions and chemical oxidative polymerization, which resulted in an improved electrochemical performance owing to the increased specic surface area as well as a well-aligned and interconnected structure. [33][34][35][36][37] However, there was no report on the formation of polymer nanosheets via solution casting, which is a cost-effective simple process for commercialization.…”

Section: Introductionmentioning

confidence: 99%

Substrate-independent three-dimensional polymer nanosheets induced by solution casting

Park

Lee

et al. 2021

Chem. Sci.