Nanocomposites and nanomaterials

Electro -transport properties of ultraviolet irradiated carbon nanotubes
Marinin O.1, Ovsiienko I.1, Len T.1, Pozhidaeva A.1, Prylutskyy Yu.2, Matzui L.1, Naumova D.3, Ritter U.4 
Taras Shevchenko National University of Kyiv, 01601, Kyiv, Volodymyrska st. 64/13, Departments of Physics1, Biohysics2 and Chemistry3
4Ilmenau University of Technology, Department of Chemistry, Weimarer-Str. 25, 98693 Ilmenau, Germany
E-mail: marininoleg907@gmail.com 
The present paper is devoted to questions of possibility of carbon nanotubes (CNT) functionalization under ultraviolet irradiation and influence of this irradiation on the transport properties CNT. Three types of specimens were chosen for investigations: as received multiwall CNT (MWCNT), as received single wall CNT (SWCNT) and MWCNT, functionalized with nitric acid (CNT-COOH). The qualitative composition of functional groups on the CNT surface was determined by method of IR-spectroscopy. For investigations of resistivity bulk specimens from CNT have been prepared by cold compacting with binder. The measurements of resistance ((T)) were carried out by standard four probe method in temperature interval from 4.2K to 293K.
Figure presents the temperature dependence of resistivity (T) for initial and irradiated bulk CNT specimens. 

Figure. The dependence (T) for initial and irradiated CNT bulk specimens	It is shown that UV irradiation of SWCNT carbon nanotubes results in decrease of resistivity in comparison with initial SWCNT. For MWCNT UV irradiation doesn’t substantially affect on the nanotubes resistivity. And for functionalized MWCNT irradiation leads to a significant increase of resistivity by breaking electronic system and localization of electrons by functional groups, аnd also leads to increase of contact resistance between the individual tubes.