Crosslinking electrochemically prepared films

Electrochemical polymerisation produces films on an electrode surface.. Under controlled conditions uniform films up to a few mm thick, which carl be removed from the electrode for subsequent study, can be prepared. Physical properties can be modified by choice of the counterions (dopants) included in the film during growth. It is, however, more difficult to control chain structure and crosslinking than in chemical methods. Electrochemically produced polymers are, therefore, less well characterised than the best directly-synthesised polymers. While this is less satisfactory for fundamental investigations, it is of less concern for applications such as battery electrodes, artificial muscles and drug release agents. The two main approaches, direct-synthesis and electrochemical, are described in the following two sections. 

Electrochemical polymerisation provides a facile method for the preparation of films of insoluble polymers for both fundamental and applied research. However, it is difficult to ensure that there is a single reaction leading to a unique polymer. The polymers are more often complex, crosslinked materials that may be suitable for practical applications, but are difficult to characterise. Because of the complexities of both the electrochemical polymerisation and the structure and properties of the polymers so produced, these topics will continue to be the subjects of research. 

First-generation Rug dendrimers 8.44 have been prepared, and the incorporation of functional groups allowed the fabrication of crosslinked films. Electrochemical studies showed that for each Ru2 unit two one-electron oxidations are detected, with a very large redox coupling (AE1/2 0.55 V). Materials 8.44 are of considerable interest, as one-electron oxidation of each RU2 unit leads to mixed-valence... 

An SPE composed of a three-dimensional crosslinked compound, using a diacrylic acid ester compound and/or a dimethacrylic acid ester compound, was reported for use in electrochemical devices. Nanocomposite SPE films composed of PEO, lithium triflate (LiCEgSOs) and Si02 nanofiller (15 nm in size) were prepared by using the solution-cast method. At room temperature, PEO-LiCFsSOs (88 12 w/w) showed a high ionic conductivity of about 1.28 x 10 S/cm. 

---