Lu Gan

Covalently functionalized graphene with D-glucose and its reinforcement to poly(vinyl alcohol) and poly(methyl methacrylate)

Chemically functionalized graphene has been synthesized by covalently grafting D-glucose on graphene for the first time through an esterification reaction. The D-glucose functionalized graphene was further applied in the preparation of poly(vinyl alcohol) and poly(methyl methacrylate) nanocomposites. The thermal and mechanical properties of the prepared nanocomposites were then investigated. It was demonstrated that the D-glucose was grafted on the surface of the graphene through a covalent attachment. The chemically functionalized graphene had better dispersibility in both water and dimethylformamide than the pristine graphene. The better dispersion of the functionalized graphene in both aqueous and organic solvents simplified the preparation of the polymer nanocomposites. It was found that the D-glucose grafted graphene dispersed homogeneously in both poly(vinyl alcohol) and poly(methyl methacrylate) matrices, increasing the thermal and mechanical properties of the polymers at the same time. The phenomena were ascribed to the introduction of the D-glucose, which induced strong hydrogen bonding interactions between the functionalized graphene and the polymers. The results of this study indicate that this is an effective approach for preparing well-dispersed graphene-based polymer nanocomposites by covalently attaching functional molecules on the surface of graphene.

Alginic acid/graphene oxide hydrogel film coated functional cotton fabric for controlled release of matrine and oxymatrine

The present study describes the fabrication of a functional cotton fabric in which an alginic acid/graphene oxide hydrogel layer was coated on the surface of cotton fabric. The functional fabric was then used to absorb and release two classic Chinese traditional drugs, matrine and oxymatrine, to investigate the controlled release capability of the functional fabric. The obtained results indicated that the prepared functional fabric has a sandwich structure. This structure significantly enhanced the absorbing capability of the cotton fabric for both water and the two drugs. Moreover, with the incorporation of the graphene oxide, the functional cotton fabric could steadily release the absorbed drugs and prevent burst release. It was also found that the release speed of the two drugs could be controlled through tuning the environmental temperature. The prepared functional cotton fabric has large application potentials in many external medical care fields.

Graphene oxide incorporated alginate hydrogel beads for the removal of various organic dyes and bisphenol A in water

In the present study, we described a facile preparation of graphene oxide incorporated alginate hydrogel beads (SA/GO) and applied them in adsorbing organic pollutants in aqueous media. The results show that the incorporation of graphene oxide obviously decreased the pore size and swelling ratio of the hydrogel beads. The existence of the GO also significantly enhanced the adsorption capability of the SA/GO beads to various organic dyes, including heterocyclic dye, indigo dye, anthraquinone, and azo dye. Besides, the SA/GO beads show promising adsorption capability to the bisphenol A (BPA), a toxic chemical which could cause endocrine disruption. The adsorption isotherm and kinetic of the SA/GO beads were also studied in detail. The present study indicates that the SA/GO beads are a type of effective absorbent for various organic pollutants which have the potential to be applied in water purification fields.

Highly efficient visible-light photocatalyst based on cellulose derived carbon nanofiber/BiOBr composites

There is an urgent need to explore alternatives to replace traditional carbonaceous materials because of dwindling oil reserves and increasing atomospheric carbon dioxide. In the present study, the cellulose derived carbon nanofibers (CCNF) were prepared and used to hybridize with bismuth oxybromide to prepare novel photocatalyst composites (CCNF/BiOBr). The structural properties of the prepared composites were then characterized. Afterwards, the photocatalytic performance of the CCNF/BiOBr composites was investigated through degrading rhodamine B (RhB) under continuous visible light irradiation. The results indicated that the pyrolysis process could convert the cellulose to carbon nanofiber with high graphitization degree. The photocatalytic performance of the CCNF/BiOBr composite was better than that of the pure BiOBr, which was ascribed to the introduction of the CCNF into the composite system. The present work provides a promising way to design new photocatalyst composites with desirable carbon alternatives from biomass materials for effective treatment of organic contaminants in water media.Graphical Abstract