Abstract Composite materials containing multi-walled carbon nanotubes (MWNT) in polyolefine (polyethylene and polypropylene) matrix were prepared by coagulation precipitation. The morphology and structure of produced composites was investigated by scanning and transmission electron microscopy. Thermal analysis (oxidation in air) was performed for composites in temperature range 20–500°C. It was shown that the addition of MWNT increases the thermal stability of composites. Electrophysical properties of MWNT/PSt composites were investigated using a four-probe technique. Observed electrical percolation threshold of composite materials is near to 3–3.5wt%. Electromagnetic (EM) response of prepared materials was investigated in broadband region (26–37 GHz and 250–500 GHz). It was found that the EM response of MWNT/polyolefine depends on their electrophysical properties with percolation threshold near 2–3wt%. Keywords: Carbon nanotubespolyethylenepolypropylenecompositeselectromagnetic properties Acknowledgments This work was supported by Rus. State. Contracts ## 16.740.11.0016, 16.740.11.0146, and 16.516.11.6099, RFBR grant # 11-03-00351 and ISTC project B-1708.

Polypropylene

Thermal Stability

Percolation (cognitive psychology)

10.1080/1536383x.2012.655956

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Citations (31)

Electrophysical and Electromagnetic Properties of Pure MWNTs and MWNT/PMMA Composite Materials Depending on Their Structure

Fullerenes Nanotubes and Carbon Nanostructures (2010)

И. Н. Мазов В. Л. Кузнецов С. И. Мосеенков А. В. Ищенко А. И. Романенко

Abstract Three types of carbon multi-walled nanotubes (MWNT) with different morphology and mean diameter (7.5, 10.5, 22 nm) were used to produce polymethylmetacrylate-based composites (MWNT/PMMA) with variable MWNT loading (0.5–5wt%). The electrophysical properties of produced composites and electromagnetic response in frequency range of 2–12 GHz were investigated. Electrical conductivity of composites depends on the MWNT type increasing with lowering of the nanotube diameter and loading in composite. Reflectance and transmittance coefficients were calculated from dielectric permittivity data and found to correlate with electrical conductivity. The highest level of EM reflection was obtained for 7.5 nm MWNT-based composites and makes the value of 0.65–0.7, whereas 22 nm MWNT/PMMA composites are more transparent for EM radiation with reflection coefficient 0.3–0.4 for the highest MWNT loading. Thus MWNT/PMMA composites demonstrate high EM shielding properties. Keywords: Carbon nanotubesCompositesElectromagnetic shielding Acknowledgments The work was partially supported by the President of RF grant #538.2009. 3, Ministry of Education and Science of RF grants RNP 2.1.1/410, 2.1.2/2125 and 2.1.1/4513, and ITSC grant #B-1708.

Reflection coefficient

Reflection loss

Christian ministry

10.1080/1536383x.2010.488184

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Citations (30)

Preparation of metal-polymer composites through the thermolysis of Fe(II), Co(II), and Ni(II) maleates

Inorganic Materials (2013)

L. I. Yudanova В. А. Логвиненко N. F. Yudanov Н. А. Рудина А. В. Ищенко

10.1134/s0020168513100142

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Citations (24)

CNT/PMMA Electromagnetic Coating: Effect of Carbon Nanotube Diameter

Fullerenes Nanotubes and Carbon Nanostructures (2012)

A. Paddubskaya P. Kuzhir В. Л. Кузнецов И. Н. Мазов С. И. Мосеенков

The study is devoted to electromagnetic (EM) response properties of polymethylmetacrylate (PMMA) filled with multi-walled carbon nanotubes (MWNT) with two different average diameters (9 and 12–14 nm). The EM attenuation and reflection in the Ka-band (26–37 GHz) provided by PMMA/MWNT were measured as a function of the functional filler content (up to 2wt%). The constitutive parameters of PMMA/MWNT composites in microwave frequencies have been found to be strongly dependent on both the nanocarbon percentage and CNT mean diameter.

Reflection loss

10.1080/1536383x.2012.656054

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Citations (5)

Multi‐walled carbon nanotubes with ppm level of impurities

physica status solidi (b) (2010)

В. Л. Кузнецов Karina Elumeeva А. В. Ищенко N. Yu. Beylina Andrey A. Stepashkin

Abstract Here multi‐walled carbon nanotubes (MWNT) of different average diameters with ppm level purity were produced by a low temperature C 2 H 4 pyrolysis on Fe‐Co type catalysts combined with forthcoming graphitization at 2200–2800 °C in argon flow. Annealed nanotubes were characterized with X‐ray fluorescent analysis, BET surface measurements, HR TEM, X‐ray diffraction, DTA analysis, and measurements of temperature and magnetic field dependences of conductivity. The graphitization of MWNT results in removal of residual catalyst metal impurities, reduction of the wall defects, and closure of nanotube tips. It was found that extent of these effects depends on MWNT diameters. It was proposed that the graphitization is caused by a significant thermal displacement and diffusion of carbon atoms at temperatures higher the Debye temperature.

Carbon fibers

BET theory

10.1002/pssb.201000211

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Citations (52)

Electron–electron interaction in multiwall carbon nanotubes

Solid State Communications (2002)

А. И. Романенко A. V. Okotrub О. Б. Аникеева Lubov G Bulusheva N. F. Yudanov

Diamagnetism

Carbon fibers

10.1016/s0038-1098(01)00448-3

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Citations (6)

Temperature Dependences of Conductivity and Magnetoconductivity of Multiwall Carbon Nanotubes Annealed at Different Temperatures

Журнал Сибирского федерального университета. Математика и физика (2011)

Sergey D. Borodanov Anatoly I. Romanenko О. Б. Аникеева В. Л. Кузнецов Karina Elumeeva

Temperature (in range 4.2-300 K) and magnetic field (in fields up to 10 kG at 4.2 K) dependences of the conductivity of two sets of multiwall carbon nanotubes with different average diameters (8-10 nm and 20-22 nm) heated at various temperatures (1600, 2200, 2600, 2800 ◦C) were investigated. Temperature dependences for nanotubes with average diameter 20-22 nm is typical for quantum corrections to conductivity of the systems with interaction electrons in two dimensional conductors with local disorder. For nanotubes with average diameter 8-10 nm temperature dependences corresponds to one-dimensional variable range hopping conductivity (VRHC). The variation of annealing temperature of MWNTs influence on the contribution of corrections to conductivity and parameters of VRHC. The magnetoconductivity of MWNTs also depends on the annealing temperature and is less than that of highly oriented pyrographite. Annealed MWNTs with average diameter 20–22 nm has a positive magnetoconductivity.

Atmospheric temperature range

Variable-range hopping

Source

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Citations (1)