Nanocomposites and nanomaterials
Electrophysical properties of polymeric nanocomposites based on cobalt ferrite and nikel ferrite modified with copper iodide
S.L. Prokopenko, R.V. Mazurenko, G.M. Gunja, S.M. Makhno, P.P. Gorbyk
Chuiko Institute of Surface Chemistry, NAS of Ukraine
17 General Naumov Str., Kyiv 03164, Ukraine
E-mail: spokopwork@gmail.com

Due to the increase of the number of electronic products and devices of wireless communication tools such as local area networks mobile telephones and other communication equipment the protection from electromagnetic radiation are actual problem. Also serious electromagnetic compatibility problems have become apparent. Considerable interest was directed to materials that absorb electromagnetic radiation with greater efficiency over a wide range of frequencies. The combination of magnetic and electrical components enables the possibility of regulating their electromagnetic characteristics, which can be used in the absorption of EMR. The above problems can be solved by developing functional composite materials.
Magnetic components promising in this direction can be ferromagnetic materials of different compound. The electroconductive component may be copper iodide, which had been widely using in catalysis, photonics, as well as in piezoelectric and other dielectric devices.
The nanocomposites CuI/ferrite were synthesized by the sol-gel autocombustion method to create the nanomaterials that effectively interact with electromagnetic radiation. For the synthesis of ferrite was used Fe(NO3)3·9H2O, grade "pur.", Co(NO3)2·6H2O of grade "pur.", Ni(NO3)2·6H2O of grade "pur." and citric acid.
Modification of the composite by copper iodide was carried out during the co-precipitation of CuI from aqueous solutions of CuSO4, KI and Na2S2O3 in the presence of the obtained ferrites CoFe2O4 or NiFe2O4.
Polymeric composite materials were prepared by mixing polychlorotrifluoroethylene (PСТFE) with the composets of CuI/CoFe2O4 and CuI/NiFe2O4 by grinding in the mechanical mill to form a homogeneous mixture, which thereafter was compressed at the polymer melt temperature of 513 K and a pressure of 2 MPa.
The real and imaginary components of the complex dielectric permittivity that were observed of the 0,32CuI/CoFe2O4/PСТFE system of 3-5 times more and the electrical conductivity 1-2 orders of magnitude larger compared to 0,32CuI/NiFe2O4/PСТFE.