Contents lists available at ScienceDirect Reactive and Functional Polymers journal homepage: www.elsevier.com/locate/react An improved metal cation capture on polymer with graphene oxide synthesized by gamma radiation A. Massoud a, ⁎ , Osama M. Farid b , R.M. Maree c , K.F. Allan a , Z. Ryan Tian d a Nuclear Chemistry Department, Hot Labs Center, Egyptian Atomic Energy Authority, P.O. 13759, Cairo, Egypt b Reactors Department, Nuclear Research Center, Egyptian Atomic Energy Authority, P.O. 13759, Cairo, Egypt c Radiation Protection Department, Hot Labs Center, Egyptian Atomic Energy Authority, P.O. 13759, Cairo, Egypt d Chemistry and Biochemistry Department, Institute of Nanoscale Materials Sciences and Engineering, University of Arkansas, Fayetteville, AR 72701, USA ARTICLE INFO Keywords: Adsorbent Removal Cobalt Strontium Polymers Graphene oxide Models ABSTRACT The enhancement of polymer capacity is extremely important for removal of metal ions from their solutions. Herein, we have used graphene oxide nano-sheets with polymer to enhance the polymer capacity towards Sr 2+ and Co 2+ ions. Therefore, poly(acrylamide-acrylic acid)- graphene oxide, p(AM-AA)GO, nanocomposite was prepared with template polymerization technique using gamma radiation as an initiator at radiation dose 40 kGy. The cross-linked p(AM-AA) with/without graphene oxide was emphasized using diferent analytical techniques such as SEM, FTIR, XRD and TGA. The obtained p(AM-AA)GO nanocomposite and pure polymer were tested for removal of Sr 2+ and Co 2+ ions from aqueous solution. The results showed that the presence of GO with p(AM-AA) enhanced the adsorption amount from 210 mg/g to 296 mg/g for Co 2+ ions while enhanced from 192 mg/g to 260 mg/g for Sr 2+ ions. The nature of adsorption was studied using theoretical models such as kinetics and isotherms models. The theoretical models displayed that the adsorption of Sr +2 and Co 2+ ions was obeyed to Langmuir isotherm, pseudo second order kinetic. In addition, the thermodynamic estimations was revealed that the adsorption process is irreversible, spontaneous nature and slightly improved with temperature rising. 1. Introduction Recently, development of new adsorbent materials with exceptional properties such as high adsorption uptake, fast adsorption rate, and mechanical strength have great attention for diferent environmental applications such as desalination, removal of risky metals from their solutions and also the separation of metals from their solutions [1]. The cooperation between two compounds (material composites) has played role in developing of materials properties for many innovative appli- cations, including improving physical/chemical properties [2]. Many studies have been founded on graphene, graphene oxide (GO), reduced graphene oxide and their derivatives to enhance the physicochemical properties of organic polymers [3–5]. Polymer/Graphene oxide nano- composites or polymer/graphene derivative nanocomposites exhibited better physical and chemical properties compared to pure polymers [6]. The performance of polymer/GO composites depend not only on the properties of the individual components but also on the interactions between the contact surface of GO and the polymer [6–9]. Previous studies have primarily concentrated on that graphene is not appropriate with organic polymers and does not enable to form homogeneous composites. In contrast, the graphene oxide sheets are more suitable to interact with organic polymers and form highly homogeneous polymer composites [10,11]. Polymer/graphene oxide nanocomposite have been used in environmental applications such as: graphene oxide with diferent materials as composites for removal of heavy metals from aqueous solution [12–17], Polyethyleneimine/ graphene oxide and hyperbranched polymer/ graphene oxide used for hazardous hex- avalent chromium [18,19] polyethylenimine /graphene oxide for re- moval of U(VI) from its solution [20], and polyacrylamide-grafted/ magnetic (RGO) nanocomposites used for adsorption of dyes and Congo red [21]. Moreover, graphene with gel and Fe 2 O 3 was used for en- vironmental pollutants degradation [22,23], Graphene with diferent materials as composites used for photocatalysis [24,25], carbon quantum dots with graphene aerogel as a metal-free catalyst applied for enhanced photosensitization efciency [26]. The term “template polymerization” usually denotes to one phase systems in which monomer, template, and the reaction product are soluble in the same solvent. Template polymerization or sometimes https://doi.org/10.1016/j.reactfunctpolym.2020.104564 Received 9 January 2020; Received in revised form 10 March 2020; Accepted 11 March 2020 ⁎ Corresponding author. E-mail addresses: ayman_mass@yahoo.com, ayman.massoud@eaea.org.eg (A. Massoud). Reactive and Functional Polymers 151 (2020) 104564 Available online 12 March 2020 1381-5148/ © 2020 Published by Elsevier B.V. T