The University of Manchester, UK
Patricia Gorgojo is Lecturer of Chemical Engineering at The University of Manchester. Her research has geared towards the development of nanostructured materials with molecular separation properties for various applications including membranes for gas separation and aqueous/organic liquid filtrations, and adsorption. More specifically her research focuses on the synthesis and characterization of layered materials such as graphene and derivatives for their application as membrane material. Low flux and poor rejections are hindering faster growth of membrane-based separations and thus, it is necessary to explore new routes of increasing permeability and selectivity; the combination of specific thin fillers and selective polymers is one promising route.
Graphene oxide (GO) and its derivatives are becoming widely investigated for their use in membranes ever since Nair, et al. reported unimpeded water permeation through helium leak-tight membranes made from the 2D material. In this work, GO and functionalized GO nanosheets were used as fillers for the fabrication of mixed matrix membranes (MMMs) and led to improved performance for water treatment in ultrafiltration (UF) and air gap membrane distillation (AGMD) applications. High flux and fouling resistant membranes for UF: GO was combined with polyethersulfone (PES) to form MMMs for UF of aqueous solutions. Also, various pore formers were added to the casting solution to increase porosity. It was found that the incorporation of 0.5 wt. % of GO increased the flux from 2 to 13 L m−2 h−1 (LMH) and the rejection of bovine serum albumin (BSA) from 89.2 to 97% compared to benchmark PES membranes. SEM analysis revealed the increased pore size and porosity, which contributed to the increased flux. The combination of pore former agent T904 with 0.3 wt. % GO increased the water flux significantly from 2 to 245 LMH. In addition, improved anti-fouling properties were also obtained. Flux-enhanced membranes for AGMD: AGMD is an emerging desalination technology with the potential to meet the challenge of global water scarcity due to its low cost and high thermal efficiency compared to other processes. High flux, robust membranes for desalination by incorporating GO functionalized with 3-(aminopropyl)triethoxysilane (APTS) into polyvinylfluoride (PVDF) were prepared and enhancements of permeate flux of 52 and 86%, respectively, were obtained. The best performing membrane contained 0.3 wt.% GO-APTS and had a flux of 6.2 LMH whilst maintaining perfect salt rejection (>99.9%) as depicted in Fig 1. These improvements were attributed to increased surface and bulk porosity, larger mean pore size and hydrophilic interactions owing to the functional groups of GO and GO-APTS. These results are evidence of the potential GO and related materials have as nanocomposite fillers in high performance membranes.