Fabrication and characterization of amidoxime-grafted silica composite particles via emulsion graft polymerization

Document Type : Research Article


1 Department of Chemistry, Quaid-i-Azam University, 45320, Islamabad, PAKISTAN

2 Department of Chemistry, Pakistan Institute of Engineering and Applied Sciences, PO Nilore, Islamabad, 45650, PAKISTAN


This study deals with the synthesis and characterization of polyacrylonitrile (PAN)-grafted silica composite particles by emulsion graft polymerization using potassium persulphate as the initiator and Tween 80 as the surfactant for potential application in wastewater treatment. The commercially available silica particles (37-70 micron) were first functionalized with vinyltriethoxysilane that were subsequently employed for the grafting of PAN via emulsion polymerization. The effect of various experimental parameters, such as varying the amount of the monomer, initiator, and the emulsifier in the feed on the grafting (%) has been investigated in detail. The maximum grafting (296%) was achieved with 6% (w/v) monomer, 0.15% (w/v) initiator, and 1% (w/v) emulsifier concentration. The nitrile groups of the PAN-grafted silica composite particles were converted into amidoxime by treating with hydroxylamine. The synthesized products in all the preparation steps were carefully characterized by various analytical tools, i.e., Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction analysis (XRD). In FTIR spectrum of the silica-grafted PAN, the appearance of the characteristic peak at 2245 cm-1 that corresponds to CN stretching confirms the successful grafting of PAN onto the modified silica particles; while the transformation of nitrile into amidoxime functionality was verified by the appearance of peaks at 1642 cm-1 and 920 cm-1. Further verification of the grafting of PAN and amidoxime formation also comes from the SEM micrographs and the XRD profiles. Finally, the obtained amidoxime-grafted silica composite particles were evaluated as an adsorbent for Cu+2 ions from the simulated wastewater for potential application in wastewater treatment. The maximum adsorption capacity of 130 mg/g was achieved at pH 5 in 2 hrs.


Main Subjects

[1] Kagan C., Mitzi D., Dimitrakopoulos C., "Organic-Inorganic Hybrid Materials as Semiconducting Channels in Thin-Film Field-Effect Transistors, Science., 286(5441): 945-947(1999).
[2] Gururaja M., Rao A.H., A Review on Recent Applications ad Future Prospectus of Hybrid Composites, Int. J. Soft. Comput. Eng., 1(6): 2231-2307 (2012).
[4] Di Martino A., Guselnikova O.A., Trusova M.E., Postnikov P.S., Sedlarik V., Organic-Inorganic Hybrid Nanoparticles Controlled Delivery System for Anticancer Drugs, Int. J. Pharm., 526(1-2): 380-390 (2017).
[5] Kaushik A., Kumar R., Arya S. K., Nair M., Malhotra B., Bhansali S., Organic-Inorganic Hybrid Nanocomposite-Based Gas Sensors for Environmental Monitoring, Chem. Rev., 115(11):4571-4606 (2015).
[7] Dzyazko Y.S., Perlova O.V., Perlova N.A., Volfkovich Y.M., Sosenkin V., Trachevskii V.V., Sazonova V.F., Palchik A.V., Composite Cation-Exchange Resins Containing Zirconium Hydrophosphate for Purification of Water from U (VI) Cations, Desalination Water Treat., 69:142-152 (2017).
[8] Haerizade B.N., Ghavami M., Koohi M., Janitabar D.S., Rezaee N., Kassaee M. Z., Green Removal of Toxic Pb (II) from Water by a Novel and Recyclable Ag/γ-Fe2O3@ r-GO Nanocomposite, Iran. J. Chem. Chem. Eng. (IJCCE), 37(1): 29-37 (2018).
[12] Moon J.K., Kim K.W., Jung C.H., Shul Y.G., Lee E.H., Preparation of Organic-Inorganic Composite Adsorbent Beads for Removal of Radionuclides and Heavy Metal Ions, J. Radioanal. Nucl. Chem., 246(2): 299-307 (2000).
[13] Jeon I.Y., Baek J.B., Nanocomposites Derived from Polymers and Inorganic Nanoparticles, Materials, 3(6): 3654-3674 (2010).
[14] Lee D.W., Yoo B.R., Advanced Silica/polymer Composites: Materials and Applications, J. Ind. Eng. Chem., 38: 1-12 (2016).
[15] Lee C.H., Park S.H., Chung W., Kim J.Y., Kim S.H., Preparation and Characterization of Surface Modified Silica Nanoparticles with Organo-Silane Compounds, Colloids Surf. A, 384(1-3): 318-322 (2011).
[16] Khan I. A., Yasin T., Hussain H., Development of Amidoxime Functionalized Silica by Radiation‐Induced Grafting, J. Appl. Polym. Sci., 134(42): 45437 (2017).
[17] Cruz S.M., Viana J.C., Melt Blending and Characterization of Carbon Nanoparticles-Filled Thermoplastic Polyurethane Elastomers, J. Elastomers Plast., 7(7): 647-665 (2015).
[18] Alver E., Metin A.Ü., Çiftçi H., Synthesis and Characterization of Chitosan/Polyvinylpyrrolidone/ Zeolite Composite by Solution Blending Method, J. Inorg. Organomet. Polym Mater., 24(6): 1048-1054 (2014).
[19] Lago E., Toth P.S., Pugliese G., Pellegrini V., Bonaccorso F., Solution Blending Preparation of Polycarbonate/Graphene Composite: Boosting the Mechanical and Electrical Properties, RSC Advances, 6(100): 97931-97940 (2016).
[20] He W., Zhang X., Yu C., Huang D., Li Y., Synthesis of Bamboo/Polyaniline Composites by In Situ Polymerization and their Characteristics, BioResources, 10(2): 2969-2981 (2015).
[21] Kolahdoozan M., Kalbasi R.J., Shahzeidi Z.S., Synthesis and Characterization of P4VP/SBA-15 Composite by In Situ Polymerization, Monatshefte für Chemie-Chemical Monthly, 143(2): 325-334 (2012).
[22] Oja P.K., Nanosiliko A., Nanosilica-Reinforced Polymer Composites, Material in Technologies, 47: 285-293 (2013).
[23] Faucheu J., Gauthier C., Chazeau L., Cavaille J.Y., Mellon V., Lami E.B., Miniemulsion Polymerization for Synthesis of Structured Clay/Polymer Nanocomposites: Short Review and Recent Advances, Polymer, 51(1): 6-17 (2010).
[25] van Herk A.M., "Chemistry and Technology of Emulsion Polymerisation." Chichester, England: John Wiley & Sons; Inc., (2013).
[26] Guyot A., Tauer K., "Reactive Surfactants in Emulsion Polymerization", in: "Polymer Synthesis", Springer, p. 43-65 (1994).
[27] Guyot A., Advances in Reactive Surfactants, Adv. Colloid. Interface Sci., 108: 3-22 (2004).
[28] Lee D.C., Jang L.W., Preparation and Characterization of PMMA–Clay Hybrid Composite by Emulsion Polymerization, J. Appl. Polym. Sci., 61(7): 1117-1122 (1996).
[31] Pulat M., Isakoca C., Chemically Induced Graft Copolymerization of Vinyl Monomers onto Cotton Fibers, J. Appl. Polym. Sci., 100(3): 2343-2347 (2006).
[32] Zare A., Morshed M., Bagheri R., Karimi K., Effect of Various Parameters on the Chemical Grafting of Amide Monomers to Poly (Lactic Acid), Fibers and Polymers, 14(11): 1783-1793 (2013).
[34] Beganskienė A., Sirutkaitis V., Kurtinaitienė M., Juškėnas R., Kareiva A., FTIR, TEM and NMR Investigations of Stöber Silica Nanoparticles, Mater. Sci. (Medžiagotyra), 10: 287-290 (2004).
[36] Zaki F.A., Abdullah I., Graft Copolymerization of Acrylonitrile onto Torch Ginger Cellulose, Sains Malaysiana, 44(6): 853-859 (2015).
[37] Xu H., Liu D., He L., Liu N., Ning G., Adsorption of Copper (II) from a Wastewater Effluent of Electroplating Industry by Poly (ethyleneimine)-functionalized Silica, Iran. J. Chem. Chem. Eng. (IJCCE), 34(2): 73-81 (2015).
[38] Atta A.M., Al-Lohedan H.A., Al-Hussain S.A., Functionalization of Magnetite Nanoparticles as Oil Spill Collector, Int. J. Mol. Sci., 16(4): 6911-6931 (2015).
[39] Shin H.K., Jeun J.P., Kang P.H., The Characterization of Polyacrylonitrile Fibers Stabilized by Electron Beam Irradiation, Fiber. Polym., 13(6): 724-728 (2012).
[41] Lee S., Kim J., Ku B.C., Kim J., Joh H.I., Structural Evolution of Polyacrylonitrile Fibers in Stabilization and Carbonization, Adv. Chem. Engineer. Sci., 2(02):275 (2012).