Chemical Engineering Journal 172 (2011) 540–549 Contents lists available at ScienceDirect Chemical Engineering Journal jo u r n al hom epage: www.elsevier.com/locate/cej Magnetic Fe 3 O 4 -graphene oxide/polystyrene: Fabrication and characterization of a promising nanocomposite M.Z. Kassaee ∗ , E. Motamedi, M. Majdi Department of Chemistry, Tarbiat Modares University, P.O. Box 14155-175, Tehran, Iran a r t i c l e i n f o Article history: Received 7 February 2011 Received in revised form 8 May 2011 Accepted 24 May 2011 Keywords: Graphene Graphene oxide Fe3O4 Nanoparticles Polystyrene a b s t r a c t Our main goals in this work were to fabricate and characterize a novel magnetic composite of graphene oxide and polystyrene (NanoFe 3 O 4 @GO/PS). Fabrication was achieved through two steps. (i) A simple and effective one-pot co-precipitation of iron (II) and (III) chlorides, in the presence of graphene oxide (GO), resulted in the fabrication of the magnetite-GO hybrid-nanoparticles (NanoFe 3 O 4 @GO). (ii) Loading of the latter over polystyrene (PS) through in situ emulsion polymerization afforded the magnetic compos- ite (NanoFe 3 O 4 @GO/PS). Besides FTIR, UV–vis, XRD, and SEM, characterizations included TEM analysis which showed Fe 3 O 4 Nps with 14 nm size evenly spread over the GO nanosheets and NanoFe 3 O 4 @GO/PS composite. Also, the TGA analysis demonstrated the anticipated thermal stabilities for NanoFe 3 O 4 @GO and NanoFe 3 O 4 @GO/PS. The ICP-ES analysis showed a loading of 52–72 wt% of Fe 3 O 4 Nps dispersed over GO nanosheets. Finally, improvement of PS properties by its loading with magnetite-GO hybrid was established through our preliminary VSM and DMTA analyses. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Graphene is a one-atom-thick sheet of honeycomb carbon lat- tice which is a very recent rising star in material science [1–3]. Following isolation of graphene in 2004, much effort has been devoted for investigating its technological applications, which lead to the awarding of 2010 Nobel Prize in Physics to Geim and Novoselov, for their “groundbreaking experiments regarding the two-dimensional material graphene” [4]. Up to date, this magic compound poses as the thinnest and strongest ever measured known material in the universe [2]. Its amazing characteristics include large surface area, as well as extraordinary electrical [3,5], thermal [6], mechanical [7], and structural properties [8], all of which make graphene a highly versatile carbon species with promising applications in composites [9–13], transparent conducting films [14–17] sensors [18,19], supercapacitors [20], nanoelectronics [21,22], batteries [23], catalyst supports [24–27], and biotechnology [28]. Single graphene sheets can be produced in large scale by the thermal expansion or chemical reduction of GO, which is a layered compound that can be synthesized by oxidation of natural graphite [29–33]. The lamellar surfaces of graphene oxide are polar because of their attached oxygenated functional groups (C O, C–O, –OH, and epoxy) [34–36]. These make GO a possible starting material for immobilization of a large number of substances including a wide ∗ Corresponding author. Tel.: +98 912 1000392; fax: +98 21 88006544. E-mail address: Kassaeem@Modares.ac.ir (M.Z. Kassaee). range of metals, biomolecules, fluorescent molecules, drugs, and inorganic nanoparticles [37–43]. Moreover, the presence of these functional groups makes GO sheets strongly hydrophilic, causing them to swell readily and disperse in water [31]. These properties along with the large specific surface area make GO a superb host for nanoparticles. The combination of ferromagnetic elements such as Ni, Co, and Fe with GO has created hybrids for electromagnetic shielding [44]. Moreover, the large specific surface area of GO with its oxy- genated functional groups has provided a desired platform for loading magnetic nanoparticles. For instance decorating magnetic iron oxide Nps on GO gives NanoFe 3 O 4 @GO with promising use in a variety of fields such as biomedicine, magnetic energy storage, magnetic fluids, catalysis, and environmental remediation [42,43]. Up to date, a number of researchers have reported methods for the preparation of GO@Fe 3 O 4 including high temperature decom- position of the precursor Fe(acac) 3 on GO [44–46], ion exchange and subsequent calcinations [47], attachment of Fe 3 O 4 Nps to GO through covalent bonding [48], adding FeCl 3 to a hot mixture of NaOH and diethylene glycol [49], hydrothermal technique [50,51], microwave irradiation [52], and chemical precipitations [53–55]. On the other hand, polymer composites are valued for being strong, durable, and multifunctional species with potential applica- tions as high performance materials. Yet, the cost of nanoparticles, their availability and the challenges that remain to achieve good dispersions pose major obstacles in their production [56]. One way to produce high performance composites is filling polymers with nanotubes [57]. A better alternative is dispersing of just a small amount of graphene in polymers which often turns them into 1385-8947/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.cej.2011.05.093