Undoping reactions

The comparatively weak reversible peaks at low potentials and strong irreversible peaks at high potentials are observed when conductive polymers are used as electrode materials in electrochemical systems. They are attributed to doping-undoping reactions and over-oxidation respectively. 

Chronoabsorptometry has also been used to determine the kinetics of doping/undoping reactions in thin films of poly(3-hexylthiophene) and... 

When, as described in the previous discussion, a conductive polymer is used as the electrode of a secondary battery, the electrochemical doping-undoping reaction is equivalent to the charging-discharging reaction. As a result. 

Figure 2. Global electropolymerization reaction of five-membered heterocycles and / -doping/undoping reaction.

Although the electrochromism of polymer films contains problems in its relatively slow response and higher electricity consumption due to the redox or doping-undoping reactions in comparison with conventional liquid crystal devices, the rich variations of the coatings, the multi-coloured displays, and the easy construction of large-area devices with polymer films should lead to interesting applications. 

The corona discharges produces oxygen ions and ozone, which may react with the photoconductor [634], As a means to circumvent possible degradation of the surface layer, an extra, protective thin layer was proposed, with high carbon content [101, 635, 636]. This would reduce silicon-oxygen reactions at the surface. Excellent electrophotographic characteristics have been obtained with a thin device comprising a 0.1-/rm-thick n-type a-Si H layer, a 1.0-/rm intrinsic a-Si H layer, a 0.1-/irm undoped a-SiCo i H layer, and a 0.014-/xm undoped a-SiCoj H layer [101]. 

New multinary hydride structures (Li-Mg-B-N-H) were successfully synthesized and characterized using LiBfVLiNLL and MgH2. These hydrides show enhanced reaction kinetics at lower temperatures due to the nanocrystalline behavior of MgH2 having large surface area. Moreover, the catalytic addition drastically reduces the thermal decomposition temperatures of Li-Mg-B-N-H when compared to undoped complex hydrides. 

Once deposited as conductive films, the heterocyclic polymers can be repeatedly cycled from the undoped to the doped forms (and vice versa) in electrochemical cells substantially similar to those used for the electropolymerisation reactions. 

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