We report the preparation of an electrostatically-coupled graphene oxide nanocomposite cation exchange membrane (CEM) based on sulfonic group containing graphene oxide (SGO) (45 wt % loading) and polyvinylidene fluoride (PVDF), where the ion exchange groups were provided by the SGO additive. SGO was prepared via the mixing of graphene oxide (GO) with a mixture derived from 3,4-dihydroxy-L-phenylalanine (L-DOPA) and poly(sodium 4-styrenesulfonate) (PSS). A mold-casting technique was developed to fabricate the free-standing nanocomposite CEM. The presence of sulfonic groups in the nanocomposite was confirmed with FTIR spectroscopy. Energy dispersive spectroscopy analysis showed the SGO was distributed across the entire membrane matrix, with minimal aggregation. The resultant SGO/PVDF nanocomposite CEM membrane demonstrated high hydrophilicity and high water uptake, but low swelling ratio. Furthermore, evaluation of the electrochemical properties of the nanocomposite CEM showed favorable ion exchange capacity (0.63 ± 0.08 meq/g), permselectivity (0.95 ± 0.04), and area resistance (2.8 ± 0.2 Ω cm 2 ). The nanocomposite CEM show good potential for use in electromembrane desalination applications.
This work focuses on the use of hybrid ionic liquids (ILs) solvents from mixtures of ILs with physical diluents as potential low viscosity solvents for biogas upgrading. The thermodynamic and thermal properties of hybrid solvents composed of [C 4 mim][BF 4 ] mixed with several diluents such as water, methanol, acetone, or N-Methyl-2-pyrrolidone (NMP) were quantified using polar soft-SAFT. Results revealed that all diluents contributed equally to reducing the solvents viscosity of the pure IL, however, at the expense of increased isobaric heat capacity, vaporization enthalpy, and sometimes, reduced solubility in the case of water addition. We find that acetone is good a diluent, yielding an acceptable increase in CH 4 and CO 2 solubility and with favorable decreases in viscosity and the heat of absorption among selected solvents. The collection of acquired results confirmed the reliability of polar soft-SAFT as an attractive and valuable platform toward the rational design of hybrid solvents for biogas upgrading.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.