EDOT monomers

In another research laboratory, surprised by the lack of success of other research groups and the previous statements about the impossibility of applying biocatalytic chemistry to polithiophenes and polypyrroles, special attention was paid to the enzymatic polymerization of the EDOT monomer [43]. In this case, the first trials succeeded and a blue-colored polymer solution was obtained after 16h of reaction (Scheme 4). As is well-known, an acidic reaction medium is suitable to increase the rate of polymerization. Protonic acids and a variety of Lewis acids catalyze the equilibrium reaction of EDOT to the corresponding dimeric and trimeric compounds without further oxidation or reaction [44]. In this work, three different pHs were evaluated (pH = 2, 4, and 6) in order to establish the optimum for adequate synthesis of EDOT. The UV-visible (UV-Vis) spectra for these three reactions are... 

HRP/IL phase. The electrical conductivity of the PANI films prepared by solvent casting from the aqueous solutions showed a relatively high and similar value even after the fifth run (Fig. 12), which demonstrates the validity of our approach and the ease of recyclability and reuse of the enzyme inside the IL. For the PEDOT, the process of recovery and reuse was successfully repeated up to ten times using the same HRP/EDOT catalytic phase (Fig. 13), further confirming the success of the synthetic approach and the ease of recyclability and reuse of the enzyme inside the EDOT monomer phase. 

The dyed Ti02 film was immersed in an acetonitrile solution containing pyrrole or bis-EDOT monomer and lithium perchlorate. The applied potential of the film was referenced to the Ag/Ag+ electrode and irradiated by a 500 W Xe lamp (22 mW/cm2, X > 500 nm). 

Chiral disubstituted PEDOTs have recently been prepared for the first time via transetherification of 3,4-dimethoxythiophene monomers with chiral glycols followed by potentiodynamic oxidation.174 An alternative approach to optically active PEDOTs has also been recently described, which involves the electrochemical polymerization of the EDOT monomer in aqueous hydroxypropyl cellulose (HPC) as a polymer lyotropic liquid crystal to give a chiral PEDOT/HPC hybrid.175 The PEDOT prepared in this chiral nematic liquid crystal exhibited optically active electrochromism in that it could be electrochemically switched between a dark blue reduced state and a sky blue oxidized form that exhibited a different CD spectrum. 

Initially, poly(vinyl alcohol] (PVA] solution was electrospun and further treated with FeCl3 solution to adsorb Fe ions on the nanofibers surface. Later, an EDOT monomer was evaporated and polymerized on the PVA surface, leading to coaxial PVA/PEDOT fibers, which were washed with distillated water, giving 140 nm PEDOT tubes. PEDOT nanotubes achieved electrical conductivity values of 61 S/cm higher than the usual PEDOT nanomaterials... 

Since the EDOT monomer is not soluble in water, its reaction with the oxidant, FeCls in water is inhomogeneous. As a result, in a rapidly mixed reaction, the polymerization occurs around EDOT droplets at the EDOT-water interface forming hollow capsule-like structures, such as the one shown in Figure 7.53. 

The unique electronic properties of PEDOT combined with the high aptitude for polymerization of the EDOT monomer have given rise to the development of many EDOT-based functional conjugated systems by using either the EDOT building block or by modification of its structure. 

EDOT monomers bearing w-iodo-alkyl and w-iodo-polyether side chains (80) have been electro-polymerized into corresponding polymers. These polymers can be rapidly and quantitatively converted into functionalized polymers under mild conditions by postpolymerization reaction with functional blocks bearing a thiolate group, as demonstrated in the case of tetrathiafulvalene (81) [ 151 ]. Application of the same procedure led to a modified electrode containing a tetrathiafulvalene core substituted by two polyether chains (82). It was shown that the binding of Pb by the polymer 82 could be electrochemicaUy driven [185]. 

While a lot of literatures concerning conducting polymer nanoparticle were published, there were limited reports on the fabrication of PEDOT nanoparticle due to the relatively low solubility of the 3,4-ethylenedioxythiophene (EDOT) monomer in aqueous media. Several synthetic methods for the PEDOT nanoparticle have been reported using seed polymerization, emulsion polymerization and dispersion polymerization. 

In the case of the PEDOT nanoparticle, DBSA was used as a doping agent and a surfactant simultaneously to form a micellar solution. Two different oxidants such as EeCls and APS were employed in order to polymerize EDOT monomer in aqueous solution. The residtant product was quite spherical and its diameter ranged from 35 to lOOnm. When ferric chloride was applied as... 

Several reports related to PEDOT-coated particles and PEDOT hollow particles have been pronounced in the literature [359,360]. Dispersion polymerization has been applied for PEDOT-coated PS particles fabrication. 100 nm PS nanoparticle was used as the core material [359]. hi order to improve the stability of the PS particle, DBSA was used as the surfactant. It was presumed that hydrophobic alkyl chains of the surfactant were positioned towards the surface of PS particles and the sulfonic acid group toward the water phase. EDOT monomer was adsorbed on the surface of the PS nanosphere and polymerization was initiated by the addition of the APS oxidant. PS-PEDOT core-shell structure was distinctively visualized by TEM. The doped PEDOT shell had a higher electron density than the PS core and the thickness of the PEDOT shell was ca. 8 nm. 

Another approach has been performed for preparation of PEDOT-coated silica core-shell particles and PEDOT hollow particles [360]. Silica particle size of 130 nm was utilized as the core seed and p-TSA was used as a good dopant. p-TSA played a role of improving the solubility of EDOT monomer... 

Recently, PEDOT nanomaterials have been fabricated in the shape of rods, tubes, thimbles, and belts through chemical polymerization in the pore of AAO membrane [368]. EDOT-fiUed AAO membrane was employed to overcome the poor solubility of EDOT monomer in water and the difficulty in controlling the reaction time. Chemical polymerization has been accom-pUshed by transferring EDOT-fiUed AAO membrane into an aqueous oxidant solution. EDOT monomer was retained in the pore of the AAO due to the extremely low solubility of EDOT in the aqueous solution. The elevated polymerization temperature and high concentrated FeCb solution increased the rate of polymerization, which resulted in the augment of wall thickness. Under these conditions, different nanostructures of PEDOT such as belt-like structure, thimble-like structure and nanorod were reaUzed by different FeCU concentration and polymerization temperatures. 

Non-destructive surface-functionalization of carbon nanofibers can be achieved by using poly(3,4-ethylenedioxythiophene) (PEDOT) since PEDOT is an electron donor and carbon nanofiber is an electron acceptor [40]. PEDOT/carbon nanofiber nanocomposites can be prepared by chemical polymerization process. This includes an initial adsorption of EDOT monomers on the carbon nanofibers, which is followed by the polymerization process. The adsorption of monomers on the fiber surface occurs due to the electrostatic n-n interaction. PEDOT poly(styrenesulfonate) (PEDOT PSS)/carbon nanofiber bilayer system is used particularly for electrode applications [41]. Such bilayer systems can be easily prepared with dip-coating technique.The advantage of dip-coating is that only a small amount of polymer will be adsorbed on the carbon nanofiber surface and hence nanometer thick coating is achievable. The surface area of electroactive materials can be enhanced in such bilayer systems prepared with carbon nanofibers. 

Synthesis electropolymerization of EDOT monomer. Redox processes similar to PT. 

The industrially useful PEDOT PSS is made by aqueous oxidative polymerization of the EDOT monomer in the presence of the template polymer PSS. PSS is a commercially available, water-soluble polymer and can serve as a good dispersant for aqueous PEDOT. Polymerization with the oxidant sodium peroxodisulfate yields the PEDOT PSS complex in a conductive, cationic form (Figure 14.2). 

However, the pot life can be enhanced by cooling the reaction mixture to 5 or more drastically by using iron(III) oxidant solutions that also contain polymerization retardant(s) [121, 122]. One-pot processes allow the manufacturer to have better control of the reaction stoichiometry and hence PEDOT film quality. Not only does a one-pot process reduce EDOT monomer yield loss, but it has also been shown that the capacitors made in this way often exhibit better capacitance recovery than those made in sequential dipping processes [123]. 

Dispersion Polymerization [Method D[. Dispersion polymerization of EDOT monomer in the presence of anionie polyelectrolyte, sodium... 

The low oxidation (p-doping) potential of poly(oxythiophene)s along with high conductivity, transparency and stability of doped state make them ideal as a transparent conductor and as a hole-transport layer in various optoelectronic devices. On the other hand, alkyl-substituted EDOT and ProDOT derivatives are suitable for electrochromic applications. However, PEDOT remains one of the most extensively studied polymers in this class due to the easy commercial access of EDOT monomer and processable PEDOT polymers (Clevios-P). 

Permeating PVDF with EDOT monomer, tap drying wifli filtration paper to remove extra monomers. 

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