Graphene Oxide‐Based Polymeric Membranes for Water Treatment

Abstract

their energy consumption is much lower than that of thermal approaches. [3] Therefore, membrane technologies are regarded as cost-effective candidates and play an increasingly important role in the treatment of natural waters and wastewaters. [4] Membrane processes for water purification and desalination can be generally classified into microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), and emerging forward osmosis (FO) according to the pore size of the membrane and the respective rejection mechanism. The materials used to fabricate the membranes cover a wide range of polymers and inorganic materials. By far, polymeric membranes are the most widespread type due to their high processability, high flexibility, and low cost. [5][6][7] Traditional asymmetric membranes that contain only one type of polymer are mainly used for UF and a few NF applications. These membranes exhibit an asymmetric porous structure that consists of a thin nano porous active layer and a microporous underlying layer. MF membranes, however, possess a relatively symmetric micro porous structure. These porous membranes are mainly fabricated by phase inversion. For RO, FO, and most NF membranes that reject nanoscale solutes, an individual nonporous, dense, and thin polyamide (PA) active layer is normally required and is deposited onto a porous support layer to ensure a high selectivity. The active layer is prepared via interfacial polymerization (IP), while the support layer can be fabricated by phase inversion. These membranes are known as thin film composite (TFC) membranes, and the layers are comprised of different polymers. TFC membranes possess superior permeability over that of first-generation cellulose acetate membranes. [8,9] Although polymeric membranes have been widely reported in scientific studies and utilized for industrial applications, they are restricted by the inherent limitations of the material, such as a permeability/selectivity trade-off and a low fouling resistance. The current ability to control the membrane structure in both molecular-level design and fabrication process is not satisfactory. [10] In the last decade, the incorporation of nanomaterials into polymeric membranes has gained considerable attention owing to the potential of the resulting materials for overcoming the above limitations. [11,12] These advanced composite membranes have shown enhanced performance with a low loading of nanoparticles (NPs), including zeolites, [13][14][15] silica, [16][17][18][19][20][21][22] Membrane technologies for water treatment and desalination are increasingly developed and utilized to address the global challenges of water security and supply. Membrane-based separations can produce water with desirable qualities from a wide range of water sources, such as groundwater, seawater, brackish water, and wastewater. However, the membranes, which are typically made from polymers, are still restricted by their inherent limitations, including a permeability/selectivity trade-off and a high fouling prop...

Effective removal of proteins using carbon‐based nanoadsorbent: relevancy to the application of membrane‐driven pre‐water treatment

“…58 Furthermore, incorporating NGO in polymeric membranes also increases the membrane's lifespan and cost-effectiveness by substantially improving its mechanical and physical properties. 59,60 Therefore, NGO also can be used as nanofiller to prepare polymer-based anti-biofouling nanocomposite membranes with an increased lifespan.…”

Atom‐Thick Membranes for Water Purification and Blue Energy Harvesting

“…Furthermore, the hydrophilic nature and low surface roughness, together with the possibility of easily decorating its surface with photoactive metal/metal oxide nanoparticles, provides additional (bio)fouling resistance to GO-based hybrid membranes. [36] Recently, an active layer of CVD graphene transferred onto a commercial PTFE membrane has been shown to display antifouling properties against surfactants and oils, and to succesfully operate in real desalination conditions. In particular, antifouling properties of graphene are attributed to the decreased hydrophobicity (with respect to pristine PTFE), surface charge neutrality and weak physisorption interactions with the foulant species investigated.…”

Fabrication and Optical Modeling of Micro‐Porous Membranes Index‐Matched with Water for On‐Line Sensing Applications

“…Micro‐porous membranes are widely used for several applications including filtering, separation, emulsification, reaction catalysis, analytical measurements, and fabric production. [ 1–7 ] Key membrane properties, such as filtering power, flow resistance and robustness, are determined by their internal structure. Moreover, degradation of membrane performance can be ascribed to structural modification or to incorporation of extrinsic particles or microorganisms that cause fouling or clogging.…”

“…Micro-porous membranes are widely used for several applications including filtering, separation, emulsification, reaction catalysis, analytical measurements, and fabric production. [1][2][3][4][5][6][7] Key membrane properties, such as filtering power, flow resistance and robustness, are determined by their internal structure. Moreover, degradation of membrane performance can be ascribed to membranes made by polytetrafluoroethylene (PTFE), have been extensively applied in several fields, from research applications to industrial processes, including water and waste water treatment, air filtration, membrane distillation, and pollutants removal.…”