, Václav Štengl
and Petra Ecorchard
250 68 Řež, Czech Republic
The graphite was exfoliated using the high intensity ultrasound. From the delaminated
nanosheets graphene oxide was prepared. Graphene oxide–polystyrene (GO–PS) composite was synthesized
using direct emulsion polymerization of styrene in the presence of graphene oxide. The as-prepared samples
were characterized by X-ray diffraction (XRD), Raman spectroscopy and infrared spectroscopy. The
morphology of prepared composite was characterized using high resolution scanning electron microscopy
graphene oxide, polystyrene, composite materials
The graphene oxide has proven to be soluble in water, is amphiphilic, non-toxic and biodegradable and
form stable colloids. The surface of graphene oxide contains epoxy, hydroxyl, and carboxyl groups, which
can interact with cations and anions.
GO–polymer composites have attracted much attention due to their unique organic–inorganic hybrid
structure and exceptional properties. Core–shell structured polystyrene-magnetite-graphene oxide composite
nanoparticles were synthesised by sequentially depositing Fe
nanoparticles and GO sheets onto the
carboxyl functionalized PS template nanoparticles through electrostatic interactions . Core–shell
structured polystyrene microspherical particles were synthesised by adsorbing the GO sheets on the PS
surface through a strong π–π stacking interaction . Wu  report the synthesis of polystyrene reduced
graphene oxide composites by a two-step in situ reduction technique, which consisted of a hydrazine hydrate
reduction and a subsequent thermal reduction at 200 °C for 12 h. A simple method was used to synthesize
the polyaniline nanofiber-coated polystyrene/graphene oxide (PANI-PS/GO) core shell composite using a
solution mixing process. GO could be easily coated on PANI-coated PS to form core shell structure through
the ring-opening reaction of the epoxide groups in the GO sheets with amine groups in the PANI nanofibers
. Polystyrene particles covered with GO sheets of nanoscale size have been successfully prepared by
aqueous mini-emulsion polymerization of styrene using GO as the sole surfactant based on a novel procedure
entailing ox-idation and chemical exfoliation of graphite nano fibres . Polystyrene-intercalated GO has
been prepared by emulsion polymerization with the aid of sodium laurel sulfate and polystyrene has been
intercalated into the interlayers of GO . Graphene oxide–polystyrene composite foaming was prepared by
blending of solution polystyrene dissolved in dimethylformamide followed by CO
supercritical drying .
reduction of graphene oxide using hydrazine hydrate. PS microspheres covalently linked to the edges of
graphene nanosheets . Yu at all present the first successful application of p-phenylenediamine-
4vinylbenzen-polystyrene modified graphene oxide for application in corrosion protection .
Corresponding author. Tel.: +420266172198; fax: +420220941502.
E-mail address: email@example.com.
2014 3rd International Conference on Environment, Chemistry and Biology
IPCBEE vol.78 (2014) © (2014) IACSIT Press, Singapore
DOI: 10.7763/IPCBEE. 2014. V78. 9
by a one-step in situ direct emulsion polymerization of styrene in the presence of GO which leads to a new
class of GO based materials and their use in a variety of applications.
Preparation of graphene
The graphene was synthesized from the natural graphite (Koh-i-noor Grafite Ltd., Czech Republic) by
unique method reported elsewhere  using a high intensity cavitation field in an ultrasonic pressurized
batch reactor (UIP1000hd, 20kHz, 2000W, Hielscher Ultrasonics GmbH, 14513 Teltow, Germany).
The graphene oxide (GO) was prepared from graphene using the modified Hummers method . In a
typical experiment, H
(60 ml), H
(3 g) were mixed in a round-
The suspension was then poured onto a mixture of ice and 30% H
yellow. The product was purified by dialysis (Spectra/Por 3 dialysis membrane) and centrifuged. Purified
GO product was obtained as a brown, honey-like suspension.
Preparation of grapheme oxide polystyrene composite
GO–PS was prepared by direct emulsion polymerization of styrene  in the presence of GO. In a
typical experiment, 0.3 g of GO was dispersed in 75 ml of distilled water in a 4-neck round-bottom flask
fitted with mechanical stirrer, condenser, thermometer and nitrogen inlet. The suspension of graphene oxide
was purged by inert gas (nitrogen or argon) for 10 minutes due to the removal of oxygen, beacuse it inhibits
free radical polymerization. Then, a mixture of 5 ml of styrene and 0.1 ml divinylbenzene was added and
reaction mixture was heated. When the reaction mixture warmed to 91 °C, 2 mL solution of sodium
4-styrenesulfonate is added (4.00 g of sodium 4-styrenesulfonate in 100.0 mL water) and then, after
3 minutes the 4 mL of the solution of potassium persulfate and sodium bicarbonate (1g K
3.5 g NaHCO
in 100 ml water) was added. The reaction mixture is continuously stirred and heated. After
4-styrenesulfonate, and 0.5 mL of the solution of potassium persulfate and sodium bicarbonate were added;
heating and stirring continuos next hour. After cooling of mixture, it was filtered and purged with ethanol.
Thereafter the composite material was dried at 85 °C.
Diffraction patterns were collected with diffractometer Bruker D2 equipped with conventional X-ray
tube (Cu Kα radiation, 30 kV, 10 mA). The primary divergence slit module width 0.6 mm, Soller Module
2.5, Airscatter screen module 2 mm, Ni Kbeta-filter 0.5 mm, step 0.00405°, a counting time per a step 1 s
and the LYNXEYE 1-dimensional detector were used.
High resolution scanning electron microscopy (HRSEM) analysis was conducted on a FEI Nova
NanoSEM scanning electron microscope equipped with an Everhart-Thornley detector (ETD), Through Lens
detector (TLD), Low Vacuum detection (LVD) HELIX and sample plasma cleaner using accelerating
voltage 4-30 kV. Samples on the carbon holder were coated with a thin gold layer using vacuum sputtering.
The Raman spectra were acquired with DXR Raman microscope (Thermo Scientific) with 532 nm
(6 mW) laser, 32 two-second scans under 10x objective of an Olympus microscope.
Infrared spectra were recorded using Nicolet Impact 400D spectrometer approximately in 4000-500 cm
range with accessories for diffuse reflectance measurement.
The scheme of GO–PS composite preparation method is outlined Figure 1a. The XRD pattern of GO and
GO–PS composite is displayed in Figure 1b. The GO pattern showed a characteristic peak at 9.35°
corresponding to an interlayer spacing of 0.945 nm, indicating the presence of oxygen and oxygen containing
orientation of GO . The XRD pattern of GO–PS composite showed two main broadening peaks. The first
at 11.55° is the polymerization peak and was attributed to the intermolecular backbone–backbone correlation
and the size of the side group, which corresponds to an approximately hexagonal ordering of the molecular
chains; the latter peak at 18.7° was amorphous halo and corresponds to the van der Waals distance .
Fig. 1: a) Scheme of preparation of graphene oxide-polystyrene composite and
b) XRD pattern of grapene oxide and graphene oxide-polystyrene composite
The DRIFT spectrum of GO is shown in the Figure 2a. The broad, intense band centered at 3450 cm
was assigned to O-H stretching vibrations of the C-OH groups and the bands at 1737 cm
were assigned to
C=O stretching vibrations of the carbonyl and carboxylic groups. The band at 1630 cm
was due to skeletal
was expression of C-OH stretching
was assigned to C-O stretching vibrations. The main vibration modes of
, v(C=C) vibration in vinyl groups
, stretching vibrations of the carbons in the aromatic ring at 1601 cm
, vibration of PS
units at 1942 cm
, symmetrical and asymmetrical stretching vibrations of the CH
groups at 2848 and
and stretching vibrations of the CH groups in the aromatic ring at 3024 and 3062 cm
Fig. 2: a) Infrared spectra of graphene oxide–polystyrene composite and its components
The Raman spectrum of GO, PS and GO–PS composite is presented in Figure 2b. In the Raman
spectrum of the GO, the G band is broadened and shifted slightly to 1605 cm
, whereas the intensity of the D
increases substantially. The G band is common to all sp
carbon forms and provides
bonded carbon atoms and the D band suggests the presence of
defects . In the Raman spectrum of GO–PS, the C-H stretch mode in the vinyl group at 3054 cm
was detected .
balls in composite. The polymer and GO form an interconnected bulk network and the GO is uniformly
dispersed in the polystyrene matrix. The small balls of polystyrene whose surface are covered by GO are
clearly seen in Figure 3b at a higher magnification.
Fig. 3: SEM images of graphene oxide–polystyrene composite a) scale 3 µm, b) scale 500 nm.
The composite material of graphene oxide–polystyrene was prepared by directly synthesis at the
laboratory scale. The composite is relatively stable and synthesis is quite well reproducible, which the X-ray
and Raman measurements confirmed. However, the distribution of individual composite parts is located
randomly. Potential applications of this composite material GO-PS lies primarily in the possibility of use as a
sorbent for heavy metals, radionuclides, and other trace elements. These abilities, however, must be validated
by long-term tests.
This work was supported by Ministry of Education, Youth and Sports No.CZ.105/3.1.00/14.0328
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