Poly 2,2-bithiophene Carbon Nanotubes

The literature devoted to PBTh/CNT composites reveals only four published articles. Three of them deal with the electrochemical properties [187,188] and the use of this composite material in the fabrication of photovoltaic devices with a high open-circuit voltage [189]. The last article, dated 2009, is devoted to the molecular structure of the composite resulting from the electrochemical polymerization of 2,2 -bithiophene on 

SWNTs in the presence of TBABF4 [190]. It is shown that (i) the electrochemical polymerization of BTh on SWNT films leads to the formation of two reaction products, doped PBTh-functionalized SWNTs and undoped PBTh-functionalized SWNTs and (ii) the functionalization process of SWNTs with PBTh involves the formation of new covalent C-S bonds between the two constituents, which induce steric hindrance effects in macromolecular chains [190]. 

The first method leads to the wrapping of the CNTs with PVK [191], in other words to noncovalent functionalization. By chemical and electrochemical polymerization of VK in the presence of CNTs, the covalent functionalization of nanotubes with PVK in the undoped [33] and the doped state [194,195], respectively, is produced. Two ways have been reported for the chemical polymerization of VK in the presence of CNTs the bulk method [33] and synthesis via direct free-radical reaction [199]. 

In comparison with bulk polymerization, for the free radical reaction of VK in the presence CNTs, PVK was reacted directly with MWNTs at 70 °C in DCB with azo-bis-izobutyronitrile (AIBN) as the radical initiator [199]. After purification, deep-grey products, which can be dissolved in common solvents such as chloroform and 1,2-dichlorobenzene (DCB), were obtained. It was confirmed that PVK was grafted onto the surface of CNTs by FTIR and Raman spectroscopy, CPS, TGA, TEM, and UV-VIS spectra [199]. 

The electrochemical polymerization of PVK in LiClOVacetonitrile solution on an SWNT electrode was studied by cyclic voltammetry [194,195], The mechanism of the electropolymerization reaction of VK on the SWNT film was characterized by three stages, chemical-electrochemical-chemical [194]. The main difference between the mechanism of electropolymerization of VK on a Pt electrode only, and an electrode covered with a SWNT film consists in the fact that during the first stage, the formation of a charge-transfer complex results in the formation of VK radical cations and the SWNT radical anions. 

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M. Baibarac, I. Baltog, and S. Lefrant, Raman spectroscopic evidence for interfacial interactions in poly(bithiophene)/single-walled carbon nanotube composites. Carbon, 47, 1389-1398 (2009). 

A. Pietrzyk et al. reported an imprinted poly[bis(2,2 -bithienyl)methane] film for a piezoelectric microgravimetry of dopamine. The MIP film contained either a 3,4-dihydroxyphenyl or benzo-18-crown-6 substituent, for selective determination of dopamine and was electropolymerized on an imderlayer of poly(bithiophene) on a Pt/ quartz resonator. The detection limit of the method was reported to be 10 nM [401]. Kan et al, on the other hand, developed a composite of multiwalled carbon nanotube (MWCNTs) and MIP with dopamine templates using the copolymerization reaction of methacrylic acid and trimethylolpropane trimethacrylate (copoly(MAA-co-TRIM)) on the vinyl functionalized MWCNT surface and used the composite for the thermo-gravimetric analysis of the template. The composite was found to be selective towards dopamine in comparison with epinephrine and the response was linear in the range of 5.0 X 10 "-2.0 X 10 M [427]. 

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