Electro-synthesis and Characterization of Polymer Nanostructures from Terthiophene Using Silica Mesoporous Films as Template

Abstract

Nanostructures of poly(2,2′:5′,2′′-terthiophene) have been synthesized using only electrochemical techniques. To this end, a porous silica film modified platinum disc was used as working electrode (Pt|(SiO 2 ) n ). The silica coating acts as a template so that the subsequent electro-polymerization occurs in their confined space pores, perpendicular to the electrodic surface. The current response of the obtained polymeric deposit is much greater than that exhibited by the solid massive polymer (generated under identical conditions but without template), accounting for the significant increase of the p-doping/undoping charge. Template removal was accomplished by treating the deposits with HF solutions. It was demonstrated that as the template is removed, the charge of the nanostructured electrodes increases even more. Electro-deposit characterization was supplemented using transmission electron microscopy, TEM, and FT-Raman spectroscopy, which revealed the obtaining of electrodes modified with polymeric nanostructures vertically aligned upon the electrode surface. Thus, a methodology employing solely electrochemical techniques that enables the obtainment of polymeric nanodeposits directly on the electrode surface was proposed. This approach allows foreseeing a significant progress in applications wherein these materials are useful, since this methodology, first tested for polythiophene, is applicable to various starting units capable of being electro-synthesized.

Vertically ordered silica mesochannel films: electrochemistry and analytical applications

“…78 Note that when using oligomeric thiophene species (e.g., 2,2′:5′,2″-terthiophene) as the starting unit, a more homogeneous and ordered PTh-nw can be obtained in mesochannels. 79,80 Similarly, poly(3,4-ethylenedioxythiophene) nanowires (PEDOT-nw), 81 PEDOT-nw/PtNPs 82 and PEDOT-nw/ polydopamine composites 83 were also prepared. PEDOT-nw/ polydopamine was employed for the selective detection of DA with a low limit of detection (LOD) in the presence of AA and UA.…”

Polyaniline nanowire arrays generated through oriented mesoporous silica films: effect of pore size and spectroelectrochemical response

“…44,47,48 They are also, in principle, ideal hard templates for the growth of nanolaments with ultra-small diameters, but this is quite challenging, as demonstrated for metal nanowires electrodeposition, for instance. 49 The generation of organic polymers by electropolymerization through vertically ordered mesoporous silica-nanochannel lms appeared to be feasible, [50][51][52][53][54][55][56][57][58][59][60] but care has to be taken to restrict the polymer growth to the nanochannels length (i.e., not outside the lm) and to ensure the durable binding of polymeric nanolaments to the underlying electrode surface (if wishing to remove the silica hard template for further use as polymer nanowire arrays).…”

Synthesis and electrochemical characterization of new ruthenium–terthiophene complexes

“…5C. Polyterthiophene p-doping/undoping process, characteristic of polythiophenes, was observed in this case [46][47][48]. The obtained anodic (Q a ) and cathodic (Q c ) charges, 0.019 and 0.017 mC, respectively, gives Q a /Q c = 1.1 ratio, implying a reversible process.…”