Search

This study reports a microfluidic device based on electrochemiluminescence detection that can be potentially operated without electricity, since it functions exploiting the concept of streaming potential-driven bipolar electrochemistry.

Electropolymerization of aromatic monomers on bipolar electrodes is emerging as promising route to the surface modification of conductive objects. Here, the authors discover that some conducting polymers propagate as fibres, opening up the possibility of growing conductive polymer networks via a wireless process.

Bipolar electropolymerization is a powerful method for wirelessly achieving site-selective anisotropic modification of bipolar electrodes (BPEs) with conducting polymers. In addition, alternating current (AC) bipolar electropolymerization was developed to induce conducting polymer fibers from the terminals of BPEs that propagate parallel to the direction of the electric field. Bipolar electropolymerization is a class of next-generation electropolymerization for obtaining hybrid materials of conducting polymers and conductive objects.

Electrochemical synthesis has become a powerful tool, but the need for an electric power supply has disadvantages when considering sustainable development goals. Here, a streaming potential generated by a laminar flow of electrolyte in a microchannel acts as a driving force for electrode reactions, enabling electrochemical oxidative polymerization of aromatic monomers without an electric power supply.

A germole-containing π-conjugated polymer is prepared from the corresponding tellurophene-containing polymer by its Te–Li exchange reaction using n-butyllithium followed by the reaction with dimethylgermanium dichloride. The low-lying LUMO energy level of the germole-containing π-conjugated polymer is also described.

Alternating π-conjugated copolymers containing 9,9-dialkylfluorene (Fl) units have been widely studied, but there are few of these copolymers with sp²-carbon functionalized Fl units. In this study, we expand this limitation by performing the anodic chlorination of alternating π-conjugated copolymers, which are composed of Fl and another arylene (Ar) (P(Fl-Ar)s), using an acetonitrile solution that contains aluminum chloride as an electrolyte. The sp²-carbon at the fluorene ring was successfully chlorinated by anodic chlorination. P(Fl-Ar)s containing sp²-chlorinated fluorene units has different emission properties from the original P(Fl-Ar)s.

The synthesis of a novel conjugated polymer containing fused pyridinium units in its main chain is reported. A precursor polymer possessing pyridine and tetrafluorophenylene moieties was reacted in the presence of Lewis acid additives to promote the intramolecular nucleophilic aromatic substitution (S_NAr) reaction. The polymer reaction with BE₃-OEt₂ gave a product polymer soluble in polar organic solvents, and the successful formation of fused pyridinium ring structures was spectroscopically confirmed. The electrochemical and optical properties of the synthesized polymers were also investigated.

Alternating current bipolar electropolymerization of 3,4-ethylenedioxythiophene (EDOT) was performed in the presence of benzoquinone in tetrabutylammonium perchlorate/acetonitrile. The obtained poly(3,4-ethylenedioxythiophene) (PEDOT) was deposited at both ends of bipolar electrode (BPE) gold wires in a linear fiber form (φ=ca. 30 μm) owing to limited accessibility of the EDOT monomer to the active site of BPEs in a micro-space. The linear growth of the PEDOT microfibers was demonstrated to be useful for application in circuit wiring.

Recent developments on bipolar electrochemistry as an effective tool for the fabrication of gradient polymer surfaces were reviewed. The electrochemical doping and reactions of conducting polymers under an applied potential distribution using bipolar electrodes have been carried out to prepare conducting polymers with composition gradients. Indirect electrolysis using an electrogenerated metal catalyst on bipolar electrodes successfully afforded gradually modified polymer surfaces and gradient polymer brushes. The newly designed cylinder bipolar electrode system is available for site-selective applications of electric potentials, which produced electrochemical patterning of conducting polymer films.

Postfunctionalization of aromatic C – H bonds at the main chains of π-conjugated polymers (CPs) is ideal for tuning various functionalities of precursor CPs. In this study, we investigated the electrochemical C – H phosphonylation of the main chain of poly(3-hexylthiophene) (P3HT). Anodic phosphonylation of P3HT was successfully achieved using trialkyl phosphite as an electrically neutral nucleophile in the presence of nonnucleophilic dopants. The chemical structures and the optoelectronic properties of phosphonylated P3HT were characterized. The introduction of phosphonate moieties into the main chain of CPs is potentially useful for improving their processibilities and imparting sensing abilities to them.

Poly(fluorene) composed of alternating structures are considered to assume an ordered macrostructure involving lamellar and π–π stacking in the film state. The ordered structure gives rise to perfect interpolymer excimeric luminescence, which can be used as a luminescence layer in an electroluminescent device.

Tellurophenes are increasingly used in organic electronics and incorporated into devices, but their redox chemistry is poorly understood. Here the nucleophilicity of anions is shown to change the electrochemical redox behaviour of 2,5-substituted tellurophenes.

The precision synthetic method of well-defined polymer microspheres by the π-allylnickel-catalyzed living coordination polymerization of allene derivatives under the dispersion polymerization conditions is described. Unlike the conventional dispersion polymerization systems, the use of a bifunctional monomer, 1,4-diallenoxybenzene, to this living dispersion polymerization successfully gave well-defined crosslinked living polymer microspheres that exhibit high solvent-tolerant properties. The postpolymerization of functional allene monomers in the living dispersion polymerization also proceeded smoothly to give functionalized polymer microspheres that enabled their applications to the solid-phase organic synthesis and the solid-supported transition metal catalysts.