High flux ethanol dehydration using nanofibrous membranes containing graphene oxide barrier layers

Abstract

In this study, pristine multilayered graphene oxide (GO) was coated by established methods onto a thinfilm nanofibrous composite (TFNC) mat to form a high flux membrane for ethanol dehydration. The thickness of the GO layer was controlled from 90 to 300 nm by taking advantage of the self-assembly behavior of GO sheets. The low transfer barrier of the TFNC mat provides a distinct advantage due to its large bulk porosity (80%) with fully interconnected pore structures. Ethanol dehydration experiments showed that a 93 nm thick GO membrane had a permeate flux of 2.2 (kg m À2 h À1 ) and a separation factor of 308 with a feed solution containing 80 wt% ethanol and 20% water at 70 C, making the GO-TFNC system superior to commercial polymeric membranes. For example, the permeate flux of GO-TFNC is twice as high as that of the polyvinyl alcohol (PVA)-based commercial membrane. The morphology of the GO-TFNC membrane and the mechanism of water transport in the GO layer were also elucidated using SEM, TEM and grazing incidence wide-angle X-ray scattering (GIWAXS) techniques.

Graphene Oxide: A Novel 2‐Dimensional Material in Membrane Separation for Water Purification

“…To avoid swelling of GO membranes, chemical bonding was introduced into GO membranes to “lock” GO flakes in the adjacent layers . GO membranes can also be stabilized using cross‐linking agents, such as multivalent ions, diamine, or dyadic monomers . Via a LBL deposition technique, TMC was used to cross‐link adjacent GO flakes .…”

Fabricating graphene oxide-based ultrathin hybrid membrane for pervaporation dehydration via layer-by-layer self-assembly driven by multiple interactions

“…Moreover, GO bears abundant hydrophilic groups [11], imparting great potential for broad application in water-permeating membranes [12,13]. Therefore, fabricating layered polymer/GO hybrid membrane via LbL self-assembly seems a promising strategy to obtain ultrathin, defect-free and stable active layer.…”

Prospects of Membrane Science Development

“…Thus, its oxidized form (graphene oxide) is used for the preparation of highly efficient pervaporation membranes with superthin selective layers. It was shown that a membrane made of graphene oxide (GO) with a thickness of 93 nm can provide a permeate flux of 2.2 kg m −2 h −1 and a separation factor of 308 in the case of pervaporative dehydration of a 80 wt % ethanol aqueous solution (70°C) [186]. In [187], in the case of dehydration of a 70 wt % aqueous solution of isopropanol (70°C), a composite membrane made of GO on a porous polyacrylonitrile substrate demonstrated a flux of 4.4 kg m −2 h −1 and a separation factor of 1160.…”