Polythiophene composites

C. Lagrost, J. C. Lacroix, S. Aeiyach, M. Jouini, K. Chane Ching, and P. C. Lacaze, Host guest complexation a new strategy for electrodeposition of processahle polythiophene composites from aqueous Medium, Chem. Comm., 489-490 (1998). 

A.J. Miller, R.A. Hatton, and S.R.P. Silva, Water-soluble multiwall-carbon-nanotube-polythiophene composite for bilayer photovoltaics. Applied... 

Chen et al. reported the synthesis of sulfur/polythiophene composites with core/shell structure through an in-situ chemical oxidative polymerization method for LIB cathode. Using a low viscosity electrolyte of 1,3-dioxolane (DOL)/dimethoxy ethane (DME), the composite with 72 wt% of sulfur was cycled at a current density of 100 mA/g and retained 74% of its initial capacity (1120mAh/g) after 80 cycles [47]. Polythiophene (PTh) coated with ultrathin MnO nanosheets was synthesized through one-step aqueous/ organic interfacial method for LIB anode application. The as-synthesized MnOj-polythiophene nanocomposite delivered a reversible capacity of 720 rnAh/g and retained 500 mAh/g after 100 cycles at a high current density of 500 mA/g [48]. 

Xie Y, Hong X, Wang X et al (2012) Preparation and electromagnetic properties of La-doped barium-ftarite/polythiophene composites. Synth Met 162 1643-1647... 

Thus, ellipsometry gives direct evidence for a model of the initial stages of polythiophene growth, disproving the conclusions based purely on coulo-metry. In the same paper, Hamnett and Hillman were able to obtain valuable and complementary information not just on the initial stages of the polymerisation but also on the mechanism of the subsequent nucleation and growth. The unique piece of information that the ellipsometer was able to extract, the changes in film thickness (in real time), when combined with coulometric data allowed a wealth of information to be deduced, e.g. with respect to the film composition, and ably showed the power of the technique. 

Guan H, Zhou P, Zho X, He Z (2008) Sensitive and selective detection of aspartic acid and glutamic acid based on polythiophene-gold nanoparticles composite. Talanta 77 319-324... 

Polythiophenes (PTs)/CNTs composites have emerged as an intriguing system for use as photovoltaic devices and field effect transistors [57]. Swager and Bao independently reported methods for the assembling of PTs/CNTs systems and showed their great potential as transparent conductive films [58]. Another interesting application arises from the possibility to functionalize the polythiophene backbone for applications as chemical sensors [134]. 

Composites can also be prepared by electropolymerization from solutions containing dissolved polymer 307). Since films of polypyrrole or polythiophene are normally porous, it seems most likely that the dissolved polymer is simply entrained in the pores. Similarly, composites have been prepared by polymerization of pyrrole in the presence of acrylic latex, giving blends with 10-30 % polypyrrole that are conducting yet processable 808). Presumably the polypyrrole is distributed throughout the latex particles. 

Polythiophene lends itself to the same routes to composites. A poly(3-methyl-thiophene)-poly(methylmethacrylate) composite has been made by electrochemical polymerization from a solution of thiophene and PMMA in methylene chloride and nitrobenzene. At high current densities the electrode side quickly became highly conducting while the outer side was less so 307). Similar composites have been prepared by chemical routes, using a Grignard reaction, firstly to couple the thiophene units in a step-reaction, then to initiate the polymerization of the methyl methacrylate 315). 

Novel hybrid materials have been realized in which fullerenes participate in composite films with 7r-conjugated-polymer electron donors such as oligothio-phenes. Established studies have already shown that the photoinduced electron transfer is rather enhanced between 7r-conjugated polymers and fullerenes, while back electron transfer is considerably slower [145,149,171,172].Electrosynthe-sized polythiophene with pendant fullerene substituents was recently obtained from the corresponding biothiophene-fulleropyrrolidine dyad [173]. The novel material described has the potential of a double-cable polymer, heavily loaded with fullerene electron-conducting moieties. 

Intercalation of electroactive polymers such as polyaniline and polypyrrole in mica-type layered silicates leads to metal-insulator nanocomposites. The conductivity of these nanocomposites in the form of films is highly anisotropic, with the in-plane conductivity 10 to 10 times higher than the conductivity in the direction perpendicular to the film. Conductive polymer/oxide bronze nanocomposites have been prepared by intercalating polythiophene in V2O5 layered phase, which is analogous to clays. °° Studies of these composites are expected not only to provide a fundamental understanding of the conduction mechanism in the polymers, but also to lead to diverse electrical and optical properties. 

Composites of polypyrrole and poly(vinyl chloride) have been prepared by several groups (64-67). Polythiophene-poly(vinyl chloride) composites have also been prepared (68). The electropolymerization of pyrrole on poly(vinyl chloride)-coated electrodes yielded composites with mechanical properties (tensile strength, percent elongation at break, percent elongation at yield) similar to poly(vinyl chloride) (65) but with a conductivity of 5-50 S/cm, which is only slightly inferior to polypyrrole (30-60 S/cm) prepared under similar conditions. In addition, the environmental stability was enhanced. Morphological studies (69) showed that the polypyrrole was not uniformly distributed in the film and had polypyrrole-rich layers next to the electrode. Similarly, poly(vinyl alcohol) (70) poly[(vinylidine chloride)-co-(trifluoroethylene)] (69) and brominated poly(vinyl carbazole) (71) have been used as the matrix polymers. The chemical polymerization of pyrrole in a poly(vinyl alcohol) matrix by ferric chloride and potassium ferricyanide also yielded conducting composites with conductivities of 10 S/cm (72-74). 

Oxide, flouride, and polymeric films, as well as certain others, are used as protective coatings for HTSC materials (for example, see [505]). The electrodeposition of conducting polymers such as polypyrrole [433,491, 493, 506], polythiophene and its derivatives [493, 507], and polyaniline [478] is the most effective process. Anodic electropolymerization in acetonitrile solutions proceeds without any degradation of the HTSC substrate and ensures continuous and uniform coatings. Apparently, this method is promising not only for the fabrication of compositions with special properties based on HTSC [50, 28,295] as mentioned above, but also for the creation of junctions with special characteristics [507]. 

Rud et al. applied electric fields for the improved vertical orientation of SWNTs in a blend with a water-soluble polythiophene derivative [323]. A profound increase of both the conductance and the photocurrent was observed for the devices where CNTs were aligned. The orientation of MWNTs in composites with polymers can also be influenced by application of large magnetic fields [324]. 

Gadisa A, Svensson M, Andersson MR, Ingantls O (2004) Correlation between oxidation potential and open-circuit voltage of composite solar cells based on blends of polythiophenes/fullerene derivative. Appl Phys Lett 84 1609... 

A great deal of work has been done to characterize the structure of films cast from chemically prepared polythiophenes.96 Most of this work has been conducted on undoped PTh s because of their importance in electronic devices, such as thin-film transistors and photovoltaics. Depending on composition and processing conditions, the crystallinity can be as high as 30% in polythiophenes.97 A layered structure is usually formed in PTh crystals between extended chains held together by ir-slacking, with additional structural order introduced by alkyl side-chain interactions in functionalized PTh s.98 Chemically synthesized PTh powders exhibit a... 

This group of polythiophenes is of considerable interest, both because the materials are intermediate between the plain PT and the PATs, and because they can be used to study the effect of head-to-tail versus head-to-head/tail-to-tail-configuTat ons. The materials may be considered as co-polymers of thiophene, T, and alkylthiophenes, AT and TA, with general compositions [(AT),(T),(TA),L ( exo ) or [(TA),(T),(AT),] Cendo ) (or also [(AT)r(T) (AT),] ), where AT and TA differ by the point at which the alkyl side chain is attached to the... 

Electrically conducting polystyrene/polythiophene, polystyrene/polypyrrole, polyacrylonitrUe/poly-pyrrole, polycarbonate/polythiophene, polycarbonate/polypyrrole composites are prepared by... 

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