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

ABSTRACT 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 Δ G ° 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.