Spectroscopic Investigations on Polyethylene - Functionalized Single Wall Carbon Nanotube Composites

摘要

Electron spin resonance (ESR) has been widely utilized to identify,analyze,and characterize carbon nanotubes (CNT) [1-5]. The ESR spectrum of CNT consists typically of up to three lines [1-5]. The low field (large g-value) wide resonance has been assigned to catalysts residues [1-3,5]. HiPco route to produce CNTs uses Fe carbonyl as catalyst [1]. The process leaves nanometer sized iron clusters,which are coupled by exchange interactions,within CNT. The narrow resonance line located close to the free electron g-value (g=2.0023) has been assigned to conducting electrons residing on single wall carbon nanotube (SWNT) [1,5]. The broad resonance line located near g=2.0023 has been assigned to amorphous carbon or graphite residues [5]. Fluorine is an extremely reactive molecule; it reacts with carbonaceous materials and affects significantly their physical and chemical properties. The fluorination of graphite (actually intercalated graphite) results in a material with outstanding DC conductivities (about 105 Scm-1). Higher fluorine concentrations are responsible for the formation of C-F covalent bonds and finally the decrease of the DC conductivity. CNTs functionalization aimed either to the control of the electric properties of these one dimensional carbonaceous materials or to a chemical control of their interface.