title: Graphene-Embedded Hydrogel Nanofibers for Detection and Removal of Aqueous-Phase Dyes.
abstract: A facile route to graphene/polymer hydrogel nanofibers was developed. An aqueous dispersion of graphene (containing >40% bilayer graphene flakes) stabilized by a functionalized water-soluble polymer with phenyl side chains was successfully electrospun to yield nanofibers. Subsequent vapor-phase cross-linking of the nanofibers produced graphene-embedded hydrogel nanofibers (GHNFs). Interestingly, the GHNFs showed chemical sensitivity to the cationic dyes methylene blue (MB) and crystal violet (CV) in the aqueous phase. The adsorption capacities were as high as 0.43 and 0.33 mmol g-1s-1for MB and CV, respectively, even in a 1.5 mL s-1flow system. A density functional theory calculation revealed that aqueous-phase MB and CV dyes were oriented parallel to the graphene surface and that the graphene/dye ensembles were stabilized by secondary physical bonding mechanisms such as the π-π stacking interaction in an aqueous medium. The GHNFs exhibited electrochemical properties arising mainly from the electric double-layer capacitance, which were applied in a demonstration of GHNF-based membrane electrodes (5 cm in diameter) for detecting the dyes in the flow system. It is believed that the GHNF membrane can be a successful model candidate for commercialization of graphene due to its easy-to-fabricate process and remarkable properties.
authors.forename: Kyungun
authors.initials: K
authors.lastname: Im
authors.forename: Duong Nguyen
authors.initials: DN
authors.lastname: Nguyen
authors.forename: Saerona
authors.initials: S
authors.lastname: Kim
authors.forename: Hye Jeong
authors.initials: HJ
authors.lastname: Kong
authors.forename: Yukyung
authors.initials: Y
authors.lastname: Kim
authors.affiliation: BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB) , Daejeon 34141, South Korea.
authors.forename: Chul Soon
authors.initials: CS
authors.lastname: Park
authors.affiliation: BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB) , Daejeon 34141, South Korea.
authors.forename: Oh Seok
authors.identifier: http://orcid.org/0000-0002-5936-244X
authors.initials: OS
authors.lastname: Kwon
authors.forename: Hyeonseok
authors.identifier: http://orcid.org/0000-0002-5403-1617
authors.initials: H
authors.lastname: Yoon
keywords: adsorption; dyes; graphene; hydrogels; nanofibers; sensors