Reduced graphene oxide decorated superporous polyacrylamide based interpenetrating network hydrogel as dye adsorbent

Abstract

Herein, nano-CaCO3 is utilized as exfoliating pore forming agent to enhance the structural porosity of reduced graphene oxide based hybrid polyacrylamide (PAAm) hydrogel for the application of dye removal. The structural incorporation of microcrystalline chains (MCC) to the hydrogel structure is adopted to form stable interpenetrating polymer network, whereas; in situ reduction is performed onto the leached nanocomposite hydrogel to enhance the dye removal behavior for all dyes. The prepared MCC/poly (AAm-co-NaAc) nanocomposite hydrogel is morphologically and structurally characterized with SEM, TEM, XRD and FTIR. Thermal and viscoelastic behaviors of the porous nanocomposite hydrogel are evaluated through TGA and rheometer. Surface pattern of nano-CaCO3 leached and unleached nanocomposite hydrogels are explored through AFM measurements, while superporous feature of the nanocomposite hydrogel is analyzed through BET adsorption isotherm and mercury porosimetry. Moreover, pH responsive swelling behavior of the nanocomposite hydrogel is well studied along with detail investigation towards removal of dye pollutants (MB/RhB) with respect to contact time and solution temperature.