Green synthesis of porous polyvinyl alcohol membranes functionalized with l-arginine and their application in the removal of 4-nitrophenol from aqueous solution

Green and single-step synthesis of porous poly(vinyl alcohol) membrane functionalized with l -arginine (PVA-g-Arg) is presented. Crosslinking, l -arginine functionalization and pore forming occurred simultaneously by a thermally induced process without using a crosslinker or an initiator. As-synthesized PVA-g-Arg membranes possessed a porous structure with an average pore size of 32–56 μm depending on the amount of l -arginine. The PVA-g-Arg were utilized as adsorbent membranes for the removal of 4-nitrophenol (4-NP) from aqueous solutions and demonstrated higher adsorption capacity than that of the unmodified PVA porous membrane. The pseudo-second-order described satisfactorily the kinetic adsorption of 4-NP by the membranes while the isotherms followed both the Langmuir and Freundlich models. The negative values of ΔG° and thermodynamic parameters confirmed that the adsorption of 4-NP by the PVA-g-Arg membranes was spontaneous and exothermic. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47835.