Fabrication of hydrogel of hydroxypropyl cellulose (HPC) composited with graphene oxide and its application for methylene blue removal

Novel environmental friendly hydroxypropyl cellulose (HPC) hydrogels were fabricated upon compositing with graphene oxide (GO) in this work. In order to promote a more homogeneous dispersion of GO sheets in HPC, GO was firstly modified with HPC chains through esterification. The morphology and chemical structure of the functionalized HPC-GO were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometer, X-ray diffraction, and thermo-gravimetric analysis. Then scanning electronic microscope was employed to compare the morphologies of the HPC and HPC-GO/HPC hydrogels. The obtained HPC-GO/HPC hydrogels exhibited excellent adsorption performance toward methylene blue. Simulation of the practical use by preparing simple adsorption columns made from in situ formation of HPC-based hydrogels had given a visible observation of the significant adsorption effect brought by the incorporation of HPC-GO sheets. Adsorption kinetics were then imitated by Lagergren pseudo-first-order and pseudo-second-order models. Adsorption isotherms were imitated by Langmuir isotherm and Freundlich isotherm.