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Covalent immobilization of laccase on Fe3O4-graphene oxide nanocomposite for biodegradation of phenolic compounds

Rouhani Shamila, Azizi Shohreh, Maaza Malik, Mamba Bhekie, Msagati Titus A. M.

Environment Protection Engineering

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2021

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Vol. 47, nr 1

85--99

EN

Laccase from Trametes Versicolor (E.C. 1.10.3.2) was immobilized on the Fe3O4–graphene hybrid nanocomposite through the covalent attachment method (Lac/Fe3O4/GO). The effect of immobilization conditions on the activity and recovered activities such as contact time, the concentration of glutaraldehyde and enzyme was evaluated. The recovered activity of the immobilized laccase on the Fe3O4–graphene oxide nanocomposite was ca. 86%. Immobilized laccase unlike free laccase retained the activity and exhibited higher resistance to temperature and pH changes and also improved storage and thermal stability. Approximately 70% of relative activity for immobilized laccase was remained after being incubated for 2 h at 55 °C, but free laccase only remained 48%. Immobilized laccase retained 88% of initial activity after storage for 20 days, however, the free laccase only 32%. Finally, Lac/Fe3O4/GO capability was evaluated by the oxidation of phenol, p-chlorophenol, and 2,4-dichlorophenol. Lac/Fe3O4/GO was characterized by SEM, EDX, FT-IR, and AGFM.

2

Thermo-magnetic stability of magnetic Fe3O4 nanoparticles for hyperthermia

Pan Y. M., Zhang W., Hu Z. F., Feng Z. Y., Zhang X. P.

Materials Science Poland

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2020

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Vol. 38, No. 4

637--643

EN

Monodispersed Fe3O4 magnetic particles adsorbed by amylase (such as citric acid (CA), carboxymethyl chitosan (CMCH) and β-cyclodextrin (CD)) were prepared by means of co-precipitation method. The absorption character of the samples was investigated by FT-IR, TG and VSM. It was found that the carboxyl (COOH groups) of amylase reacted with the hydroxyl (OH groups) on the surface of Fe3O4 particles, resulting in the formation of iron carboxylate that was adsorbed onto Fe3O4. The induction heating properties of the magnetic Fe3O4 nanoparticles in an alternating current magnetic field were also investigated and the thermo-magnetic stability in induction heating was discussed.

3

Polystyrene/magnetite nanocomposite synthesis and characterization: investigation of magnetic and electrical properties for using as microelectromechanical systems (MEMS)

Omidi M. H., Alibeygi M., Piri F., Masoudifarid M.

Materials Science Poland

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2017

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Vol. 35, No. 1

105--110

EN

In this work, a novel polystyrene/Fe3O4 nanocomposite prepared by in-situ method is presented. Magnetic Fe3O4 nanoparticles were encapsulated by polystyrene. The FT-IR spectra confirmed polystyrene/ Fe3O4 nanocomposite preparation. The electrical properties of prepared nanocomposite were investigated by cyclic voltammetry (CV). The CV analysis showed good electrical conductivity of the synthesized nanocomposite. Magnetic properties of the nanocomposite were studied by vibrating sample magnetometer (VSM). The VSM analysis confirmed magnetic properties of the nanocomposite. The morphology and the size of the synthesized nanocomposite were investigated by field emission scanning electron microscope (FESEM). According to the VSM and CV results, such nanocomposite can be used in microelectromechanical systems.

4

Synthesis and characterization of graphene oxide composite with Fe3O4

Sun C., Wang Y.

Materials Science Poland

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2015

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Vol. 33, No. 3

488--490

EN

In the paper, a magnetic composite of graphene oxide (MGO) has been successfully synthesized through decomposition of iron (III) acetylacetonate in the mixture solution of triethylene glycol and graphene oxide (GO). Atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and superconducting quantum interference device were used to characterize the material. The results show that the magnetic Fe3O4 nanoparticles modified graphene oxide composite with superparamagnetic properties, and magnetization saturation of 16.4 emu/g has been obtained. The MGO has a good sustained-release performance, and in vitro cytotoxicity confirming its secure use as a potential drug carrier.

5

Fabrication Fe/Fe3O4/Graphene Nanocomposite Electrode Material for Rechargeable Ni/Fe Batteries in Hybrid Electric Vehicles

Kumar H., Shukla A. K.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 14

15--25

EN

Fe/Fe3O4/Graphene composite electrode material was synthesized by a thermal reduction method and then used as anode material along with Nickel cathode in rechargeable Ni/Fe alkaline batteries in hybrid electric vehicles. Reduced graphene /Fe/Fe3O4 composite electrode material was prepared using a facile three step synthesis involving synthesis of iron oxalate and subsequent reduction of exfoliated graphene oxide and iron oxalate by thermal decomposition method. The synthesis approach presents a promising route for a large-scale production of reduced graphene /Fe/Fe3O4 composite as electrode material for Ni/Fe rechargeable batteries. The particle size and structure of the samples were characterized by SEM and XRD.