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A novel organic-inorganic nanocomposite membrane with green material based is prepared by incorporating sulfonated holey graphene oxide (SHGO) into nanocrystalline cellulose/polyvinyl alcohol (NCC/PVA) matrix as polymer electrolyte membrane (PEMs) via solution casting method. Introducing sulfonic acid group in graphene oxide (GO) yielded sulfonated graphene oxide (SGO) and the hole effect on the graphitic plane of GO for SHGO on NCC/PVA significantly improves the proton conductivity of membranes by creating more interconnected proton transfer channels and promoting proton transfer across the membrane. Highest proton conductivity values of 1.1 × 10-2 S cm-1 is obtained by NCC/PVA-SHGO-1.0 at 80o C under 100% relative humidity (RH). Additionally, mechanical and chemical stability tests indicate an enhancement in those properties. However, hydrogen permeation has slightly increase due to the hole effect. Increasing SHGO loading in NCC/PVA has improve its properties and performance. At 80o C, under 100% RH, NCC/PVA-SHGO-1.0 exhibit the highest power density and current density of 31.4 mW/cm2 and 60.2 mA/cm2, respectively which is three times higher compared to pristine NCC/PVA. This work summarise that incorporating SHGO into NCC/PVA membranes can significantly improves its properties, performance and membrane durability which entitle them as a potential candidate for PEMs. [Display omitted] • Sulfonation and the holey graphitic plane structure in SHGO construct additional pathways for proton transport. • Embedding fillers generate stiffer and mechanically stable PEMs as compared to pristine NCC/PVA. • At 80° C, under 100% RH, NCC/PVA-SHGO-1.0 exhibit three times higher fuel cell performance compared to pristine NCC/PVA. [ABSTRACT FROM AUTHOR]

This study involves the preparation of a double-skinned thin film composite (TFC) and thin film nanocomposite (TFN) hollow fiber (HF) membrane for forward osmosis (FO) applications. The porous substrate consisted of a Polyvinyl chloride (PVC) / Polycarbonate (PC) blend HF membrane. Interfacial polymerization (IP) was then applied to coat a polyamide (PA) layer on the lumen surface and the porous substrate's outer surface. In addition, the impact of the outer PA active layer and the addition of nanoparticles to the outer selective layer on the FO flux and internal concentration polarization (ICP) were studied. By adding the second active layer to the substrate, water flux, reverse salt flux and ICP decreased. Also, the decline of water flux decreased over time due to the fouling agent. To compensate for the decrease in water flux in the double-skinned membrane, graphene oxide (GO) nanoparticles with 0.05% and 0.1%wt were added to the outer active layer. Addition of 0.1%wt graphene oxide nanoparticle to the outer active layer can help to improve water flux about 78% without spoiling the reverse salt flux. Moreover, the performance of double-skinned membranes against osmotic dilution process for oily wastewater treatment was investigated. The findings of this study demonstrated that the novel double-skinned TFN HF membrane exhibited high FO performance with low ICP and fouling. [Display omitted] • Inclusion of a second active layer without reducing the reverse salt flux and fouling. • To improve fouling resistance of membrane, GO was added to second active layer. • By adding GO to outer active layer, reverse salt flux and fouling was reduced. • The Hermia model showed intermediate blocking in neat membrane. • The predominant fouling in double-skin membranes is cake formation. [ABSTRACT FROM AUTHOR]

• Thermal stable SPEEK membrane was fabricated with halloysite nanoclay and functionalized GO nanocomposites. • The silane and sulfonic acid group in the nanocomposite SPEEK membrane increased IEC and low methanol permeability. • The nanoclay and fGO membranes have shown significant proton conductivity and power density than pristine SPEEK membrane. Membrane-based fuel cells, particularly methanol-based fuel cells, are thriving areas with high efficiency, less material consumption, and low emission of pollutants. But commercial membranes have less thermal withstanding ability and high cost, so alternative polymeric membranes have been developed with desired properties to overcome this issue. The SPEEK membrane was fabricated with halloysite nanoclay and functionalized graphene oxide (f-GO) nanocomposites at various concentrations via dry phase inversion. The sulfonic acid group in the SPEEK and silane functionalization of GO enhanced the Ion exchange capacity from 0.22 to 0.35 meq/g which enhances the proton conductivity. Furthermore, the thermal stability and hydrophilicity of the pristine SPEEK membrane were reformed with addition of halloysite nanoclay and f-GO in SPEEK membrane. The presence of nanocomposite on the surface of the SPEEK membranes was confirmed via scanning electron microscope (SEM) analysis. The 3 wt% halloysite nanoclay and 2 wt% of f-GO composite membrane was hold the 0.47 mS cm−1 of proton conductivity and 72.2 mW cm−2 of power density, whereas pristine SPEEK membrane was 0.31 mS cm−1 and 28 mW cm−2, respectively. The 3 wt% halloysite incorporated SPEEK membrane and 1.5 wt% f-GO incorporated SPEEK membrane was shown better proton conductivity, which act as a prominent membrane for direct methanol fuel cell (DMFC) applications. [ABSTRACT FROM AUTHOR]

Tuning the ratio of sp2/sp3 is crucial factor for obtaining high aspect ratio of graphene oxide. In this work, we reported a comprehensive study on synthesis of GO with different sp2/sp3 ratios at different oxidation reaction temperatures. The physicochemical properties of the as-prepared GO were characterized by Attenuated total reflectance infrared spectroscopy (ATR-IR), Raman spectroscopy, Solid-state nuclear magnetic resonance (SSNMR), Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Transmission electron microscope (TEM), hydrophilicity test and zeta potential. Interestingly, GO-35 showed the smallest contact angle with carbon-to-oxygen (O/C) ratio 0.469. ATR-IR reveals the different intensity of hydroxyl (−OH), carbonyl (−C O), epoxy (C–O–C), as well as carboxyl (−COOH) moieties in the GO samples, and their intermolecular interactions significantly affected the interlayer spacing between consecutive identical planes of carbon atoms which examined using XRD. XPS confirmed that the basal species such as –OH is abundantly available in the GO-35 and unavailable in GO-50. Our results demonstrate that the properties of GO can be tuned using different oxidation reaction temperatures, which significantly influences types of oxygen-functional groups generated at different oxidation levels, thus could pave the way for various applications of graphene-based material. [Display omitted] • The ratio of sp2/sp3 in the GO structure can be tuned by oxidation temperature. • The integrity of graphene structure greatly decreases at oxidation temperature 50 °C. • Epoxy and hydroxyl species abundantly formed throughout the basal structure at optimum oxidation temperature, 35 °C. [ABSTRACT FROM AUTHOR]