Protonic acid doping

PANI is unique in that its most oxidized state, the pernigraniline form (which can be accessed reversibly), is not conducting. In fact, it is the intermediately oxidized emeraldine base that exhibits the highest electrical conductivity. Protonic Acid Doping is the most general means by which to obtain this partially pro-tonated form of PANI [301]. Exposure of the emeraldine salt to alkali solutions reverses this process and brings a return to the insulating state. 

Chiang J, MacDiarmid AG (1986) Polyaniline protonic acid doping of the emeraldine form to the metallic regime. Synth Met 13 193-205... 

FIG. 11.18 Conductivity of emeraldine base as a function of pH of the HCl dopant solution as it undergoes protonic acid doping ( ) and ( ) represent two independent series of experiments. From MacDiarmid, 2001. Courtesy John Wiley and Sons, Inc. 

FIG. 11.19 Oxidative doping (p-doping) of leuco-emeraldine base and protonic acid doping of emeraldine base, leading to the same final product, emeraldine salt. Reproduced from Fig. 34.3 in Mark (1996). Courtesy Springer Verlag. 

Chiang J. C. and MacDiarmid A. G., Polyaniline. Protonic acid doping of the emeral-dine form to the metallic regime, Synth. Met., 13, 193-197, 1986. 

Polyaniline holds a special position among conducting polymers in that its most highly doped form can be reached by two completely different processes protonic acid doping and oxidative doping. Protonic acid doping of emeraldine... 

These oxidation states interconvert each other, allowing the construction of a catalytic system for oxidation reaction. Actually, polyanilines or polypyrroles have been demonstrated to serve as synthetic metal catalysts under oxygen atmosphere in dehydrogenative oxidation of benzylamines, 2-phenylglycine, and 2,6-di-t-butylphenol (Scheme 3.2). " A similar catalysis is also observed with the proto-nated quinonediimine or phenylenediamine derivative, a unit of polyaniline. These catalytic activities are revealed to be controlled by protonic acid doping... 

NON-OXIDATIVE "DOPING" OF THE EMERALDINE OXIDATION STATE Protonic Acid Doping... 

J.-C. Chiang, A. G. MacDiarmid, Polyaniline Protonic Acid Doping of the Emeraldine Form to the Metallic Regime. Synth. Met. 1986, 13, 193-205. 

Due to these interactions, a weak electron donation effect occurs through the -OH group to the polymer chain and ultimately the electron flow throughout the polymer chain increases. Like protonic acid-doped PANI and its derivatives the reaction of ammonia molecule with =NH+-groups is difficult due to the steric hindrance of silver nanoparticles and the... 

FIGURE 15.1 (continued) (c) protonic acid doping of polyaniline. 

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