Recent Advances in the Electrochemical Synthesis of Copolymers Bearing π-Conjugated Systems and Methods for the Identification of their Structure

The main goal of this review is to summarise the most recent progress in the electrochemical synthesis of copolymers from conjugated co-monomers. The main approaches to electrochemical copolymerisation are highlighted and various trends in the development of new copolymer materials and the intended directions of their applications are explored. The article includes a discussion of various Authors’ approaches to investigate the structure of the obtained products, indicating the key points of interest and the importance of comprehensive identification of the products of electrochemical polymerisation.

The Different Outcomes of Electrochemical Copolymerisation: 3-Hexylthiophene with Indole, Carbazole or Fluorene

Electrochemical polymerisation is reported to be a method for readily producing copolymers of various conjugated molecules. We employed this method for mixtures of indole, carbazole or fluorene with 3-hexylthiophene (HT), in order to obtain their soluble copolymers. Although polymer films were obtained, infrared (IR) and Raman investigations showed that instead of the expected linear copolymers, polyindole and polycarbazole N-substituted with HT, as well as a poly(3-hexylthiophene) (PHT)/polyfluorene blend were produced instead. Boron trifluoride diethyl etherate was also used in an attempt to promote copolymerisation, but the produced deposits were found to be highly degraded.

Immobilising a cobalt cubane catalyst on a dye-sensitised TiO2 photoanode via electrochemical polymerisation for light-driven water oxidation

A cobalt cubane catalyst Co4O4(O2CMe)4(4-vinylpy)4 was immobilised on a dye-sensitized TiO2 electrode via electrochemical polymerization for light-driven water oxidation.

Crystal Surface/Liquid Crystal Interfacial Polymerisation: Preparation of Helical π-Conjugated Polymer on Mineral Crystal

Crystal surface/liquid crystal interfacial polymerisation was developed. Poly(3,4-ethylenedioxythiophene) (PEDOT, EDOT = ethylene dioxythiophene) and poly(EDOT-fluorene-EDOT) were prepared in a cholesteric liquid crystal electrolyte solution on the surface of pyrite. Polymerisation in liquid crystal produces polymers showing fingerprint structure through transcription of molecular aggregation in the polymerisation process. Surface structures of the polymers were observed with circular polarised differential interference contrast microscopy (C-DIM) and scanning electron microscopy (SEM). The polymerisation reaction proceeds interface between liquid crystal and pyrite surface. The polymers thus prepared in liquid crystal on the pyrite shows fingerprint structure on steps structure of pyrite. This is a first report of liquid crystal interfacial electrochemical polymerisation on a natural mineral crystal.

Polymerisation on Bio-Tissues

Preparation of electro-active polymers having characteristic surface on biological tissue was carried out. Direct polymerisation on biological material with unique structure can be a new method to obtain functional structure with no use of top-down or bottom-up technologies. Polymerisations of pyrrole, aniline, and 3,4-ethylenedioxythiophene (EDOT) were carried out on the bio-tissues. Surface structure of the bio-tissue/conducting polymer composite was observed with optical microscopy. The results of the present study involve demonstration of deposition of conducting polymers on the surface of wood, membrane of egg, fungus, flower, and bacteria in the water medium. This method allows preparation of electro-active composites with ordered structure through combination of structures of biological tissues. Note that electrochemical polymerisation in bacterial electrolyte solution can be a first example to date.

Preparation of a Ferroelectric Liquid Crystal Electrolyte Solution

A ferroelectric liquid crystal was synthesised. We attempted electrochemical polymerisation in ferroelectric liquid crystal.

A Comparison of Chemical and Electrochemical Synthesis of PEDOT:Dextran Sulphate for Bio-Application

ABSTRACTPoly(3,4-ethylenedioxythiophene) (PEDOT) is an organic conducting polymer that has been the focus of significant research over the last decade, in both energy and biological applications. Most commonly, PEDOT is doped by the artificial polymer polystyrene sulfonate due to the excellent electrical characteristics yielded by this pairing. The biopolymer dextran sulphate (DS) has been recently reported as a promising alternative to PEDOT:PSS for biological application, having electrical properties rivaling PEDOT:PSS, complimented by the potential bioactivity of the polysaccharide. In this work we compared chemical and electrochemical polymerisations of PEDOT:DS in terms of their impact on the electrical, morphological and biological properties of the resultant PEDOT:DS films. Post-growth cyclic voltammograms and UV-Vis analyses revealed comparable redox behaviour and absorbance profiles for the two synthesis approaches. Despite good intrinsic conductivity of particles, the addition of chemically produced PEDOT:DS did not markedly enhance the bulk conductivity of aqueous solutions due to the lack of interconnectivity between adjacent PEDOT:DS particles at achievable concentrations. Scanning electron microscopy revealed significantly greater roughness in films cast from chemically produced PEDOT:DS compared to electropolymerised samples, attributable to the formation of solution phase nanoparticles prior to casting. In cell studies with the L929 cell line, electrochemical polymerisation of PEDOT:DS afforded better integrity of resultant films for surface seeding, whilst chemically polymerised PEDOT:DS appeared to localised at the proliferating cells, suggesting possible applications in drug delivery.

Preparation of Polythiophene Films Showing Optical Activity by Electrochemical Polymerisation in Cholesteric Liquid Crystal Containing Coumarine

We carried out electrochemical polymerisation in a cholesteric liquid crystal electrolyte solution. The polymer film prepared in the cholesteric liquid crystal showed chiropticality even though its monomer is an achiral. The surface morphology of the polymer was observed with polarising optical microscopy. Optical and electric properties were examined by UV-vis optical absorption, circular dichroism spectroscopy, and cyclic voltammetry.