The Magnetization of a Composite Based on Reduced Graphene Oxide and Polystyrene

Abstract

The use of reduced graphene oxide (r-GO) is a promising way of fabricating organic–inorganic composites with unique electrical and magnetic properties. In our work, polystyrene/r-GO composites were synthesized, in which both the components are linked together by covalent bonds. The r-GO used differs from the graphene obtained from graphite through mechanical exfoliation using the ‘scotch tape’ by presenting many structural defects. Binding in the composite structure between the components was confirmed by infrared spectroscopy. Elemental analysis was carried out by energy dispersive X-ray analysis. Scanning electron microscopy, X-ray diffraction, and Raman spectroscopy were used to monitor the 2D-order in exfoliated r-GO galleries. Using a vibrating-sample magnetometer, we have shown that the composite magnetization loops demonstrate type-II superconductivity up to room temperature due to r-GO flakes. We believe that a strain field in the r-GO flakes covalently binding to a polymeric matrix is responsible for the superconductivity phenomena.

Magnetization of Ultraviolet-Reduced Graphene Oxide Flakes in Composites Based on Polystyrene

“…The data obtained in this work on the study of the dependence of the magnetization on the magnetic field in UV-rGO and composites based on it with PS is in complete agreement with the previously obtained results [ 14 , 46 ].…”

“…The rest of the bands belong to the stretching and torsional vibrations of the C–H bonds (3081, 3058, 3025, 1069, 1028, 758, 700 cm −1 ) [ 41 ]. The difference FTIR spectrum of the composite and the PS matrix ( Figure 4 e) demonstrates only the presence of weak signals in the region of the TMSPM absorption bands [ 14 ].…”

“…Radical polymerization with styrene and formation of covalent bonds between UV-rGO and PS chains should increase the mechanical stresses in UV-rGO flakes. It was shown in [ 14 ] that the combination of carbon flakes with paramagnetic magnetization and superconductivity could lead to the illusion of ferromagnetic ordering.…”

“…The surface of UV-rGO flakes was functionalized with TMSPM (CAS Number: 2530-85-0, Aldrich, St. Louis, MO, USA), followed by radical polymerization with styrene, forming covalent bonds between UV-rGO and PS chains [ 14 , 21 ]. We used two types of styrene: with and without ferromagnetic ordering.…”

“…This work aimed to study the magnetization of UV-reduced graphene oxide flakes [ 20 ] and their composites based on polystyrene (PS) [ 14 , 21 ] with and without weak ferromagnetic behavior. The photoreduction process results in many submicron holes distributed within the UV-rGO flakes, containing edge defective structures comprising epoxy and hydroxyl groups.…”