Poly(bisphenol) Polymers as Passivating Agents for Carbon Electrodes in Ionic Liquids

Abstract

Poly(bisphenol) polymers are identified as a new class of passivating agents for carbon electrodes in ionic liquids. They are inert and can readily be deposited as thin, conformal films by electropolymerization. Unlike conventional poly(monophenol) polymers, a single voltammetric scan is sufficient to accomplish their deposition. This is seen, for example, in the cases of poly(bisphenol A) and poly(bisphenol P). In each case, the thickness of the electropolymerized films is determined by the quantum tunneling distance of the faradaic electrons. Thus, film growth terminates when the faradaic electrons can no longer transit the film at a measurable rate. At that point, all the faradaic reactions cease, while the capacitive charging processes continue unabated. Experimentally, film thicknesses are observed in the range 4−30 nm. A challenging test for the poly(bisphenol) polymers is to coat them onto arrays of microelectrodes (RAM electrodes). Normally, microelectrodes are difficult to coat by electropolymerization due to the intense flux of soluble intermediates away from their surfaces. In the present work, however, coating is facile due to the extreme insolubility of the intermediates. This same property makes the films strongly adherent. Such remarkable behavior suggest that poly(bisphenol) films may have an important role to play as passivating agents in supercapacitors. They may also find application in other areas of technology that require thin-film passivity, such as nanostructural engineering and device physics.

Phenols as probes of chemical composition of graphene oxide

“…It has also been shown that phenolic compounds with hydroxyl groups in the meta-position tend to form polymers instead of quinones producing reduced electroactivity. 25 The number of hydroxyl groups seems to be not critical for the electrochemical behaviour since phenol and phloroglucinol presented similar trends. In addition to the known electrochemical behaviours of different phenolic compounds, our results suggest also that the compounds with reversible or quasireversible redox behaviour and with more stable oxidation products are more sensitive to the composition of the electrode surface since a little change in the amount of oxygen functionalities can generate significant alteration to their oxidation potential.…”

Proteinase-sculptured 3D-printed graphene/polylactic acid electrodes as potential biosensing platforms: towards enzymatic modeling of 3D-printed structures

“…We attribute the incomplete passivation to the large surface area and porous features of the eroded 3D-printed surfaces. Although passivating films have shown interesting properties for corrosion protection, [47][48][49] catalysis 50 and as permselective membranes in biosensor research, 46 the formation of such films has its drawbacks for electrochemistry. A few examples include the interference of electrode passivation with the electrochemical treatment of phenolic wastes, as well as with electrochemical immunoassay schemes.…”

Rutin as an Electrochemical Mediator in the Determination of Captopril using a Graphite Paste Electrode

“…Previous studies [46,47] have shown that oxidation of compounds containing quinone or phenol groups may give rise to the formation a polymer film on the electrode surface, which could impede electron transference at the electrode/solution interface. This phenomenon was observed during the investigation of rutin oxidation on a glassy carbon electrode using cyclic, differential pulse and square wave voltammetries [40], thereby rendering the use of the flavonoid as an electrochemical mediator somewhat problematic.…”