Doping, of polymers

The first use of ionic liquids in free radical addition polymerization was as an extension to the doping of polymers with simple electrolytes for the preparation of ion-conducting polymers. Several groups have prepared polymers suitable for doping with ambient-temperature ionic liquids, with the aim of producing polymer electrolytes of high ionic conductance. Many of the prepared polymers are related to the ionic liquids employed for example, poly(l-butyl-4-vinylpyridinium bromide) and poly(l-ethyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide [38 1]. 

Pseudocapacitance is used to describe electrical storage devices that have capacitor-like characteristics but that are based on redox (reduction and oxidation) reactions. Examples of pseudocapacitance are the overlapping redox reactions observed with metal oxides (e.g., RuO,) and the p- and n-dopings of polymer electrodes that occur at different voltages (e.g. polythiophene). Devices based on these charge storage mechanisms are included in electrochemical capacitors because of their energy and power profiles. 

It has been shown that the chemical and electrochemical doping of polymers may be described as a redox reaction which involves the... 

Doping of fullerenes proceeds similar to the doping of polymers. Electron donors are intercalated to the rather large octahedral and tetrahedral interstitial sites of the fee lattice and fill the originally LUMO derived band of the semicondeting pristine compound with electrons. The resulting materials are fullerides, salts of the fullerites. Basic information on the structure and properties of fullerites and fullerides can be obtained from the special... 

Labelling and doping of polymers continues to attract interest especially with regard to metal ions and pH effects. Poly(sodium styrenesulphonate-CO-vinylphenyl)anthracene copolymers have been prepared which appear to give compact conformations and are therefore able to solubilize large hydrophobic structures . Polymer bound ortho-hydroxyphenylbenzotriazoles have been found to exhibit a temperature dependent red fluorescence emission from a... 

Self-doped polypyrrole was first prepared by Reynolds et al. [42] and Havinga et al. [43] in 1987. Their approach to self-doping of polymers was based on monomers that were easier to polymerize electrochemically. Reynolds et al. prepared the N-substituted pyrrole copolymer, poly(pyrrole-co-(3-(pyrrol-l-yl)propanesulfonate)) (Figure 5.1) in acetonitrile containing tetrabutyl ammonium tetrafluoroborate as a supporting electrolyte on a platinum electrode. The monomer, potassium... 

The intercalation of dopants to conducting polymer chains leads to an increase in volume of up to 30 % [8], This property is used in actuators (polymer-based artificial muscles). Bilayer structure of polypyrrole-based anode and cathode is a simple model. At anode, p-doping of polymer occurs to swell, while the other side shrinks because of the expulsion of counterions. This volume changes promote a bend of the layers. The change of poles cancels the volume changes and gives rise to the movement in the opposite direction. 

In general, different routes for preparation of polymer electrolyte membrane based on IL have been used and classified into three categories (I) doping of polymers with IL by (a) the immersion of an already formed polymer membrane into a IL solution and (b) by mixing both IL and polymer solution for a certain period of time followed by evaporation of solvent, membranes prepared by this route have been also labeled as polymer gel-type (II) in situ polymerization or cross-linking of monomers in IL by the reactions between IL and polymeric monomers to form IL/polymer membranes ... 

Tang H, Zhu L, Harima Y, Kunugi Y, Yamashita K, Ohshita 1, Kunai A (2000) Optical study on electrochemical and chemical doping of polymers of oUgothienyls bridged by monosUyl. Electrochim Acta 45 2771-2780... 

The commercial applications of chlorosulfonic acid in the synthesis and doping of polymers are discussed in Chapter 8, p 246. 

In principle, there are mainly two methods to prepare IL-based polymer electrolytes one is doping of polymers with a selected IL (Ye et al., 2008, Subianto et al., 2009, Padilha et al.. 

Doping of polymer samples with AsFs is carried out in an all-stainless-steel vacuum line, employing either stainless steel or glass vessels with Teflon 0-ring joints. The sample tubes are first evacuated to 10 " torr, then pressurized with AsF gas to the desired pressure while maintaining the vessel at the desired temperature. After the doping time is complete, the system is evacuated to remove excess AsF. Further manipulations with doped samples may be performed in a dry box under argon. 

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