Combinational properties, electroactive composites

On the other hand, liquid phase deposition (LPD) has been demonstrated as a flexible wet chemical method for preparing metal oxide nanostructured films on electrode surfaces. By the LPD process, electroactive titanium dioxide (Ti02) films were prepared on graphite, glassy carbon and ITO. The electrochemical properties of such LPD Ti02 films were dependent upon the film thickness controlled by the deposition time. The LPD technique was easily combined with other techniques, e.g., seed-mediated growth, which could provide metal/metal oxide composite nanomaterials. Moreover, hybrid nanostructured films were facilely obtained by doping dyes, surfactants and other... 

A different approach resides in the advantageous combination of transition metal oxides with other materials being either electroactive or not. This second phase provides desirable properties that compensate the inherent limitations of the transition metal oxide resulting in a synergistic effect that enhances the electrochemical behavior of the composite. In this section, we will focus our attention in the validity of this approach to manufacture new electrode materials with excellent performances when undergoing lithium-driven conversion reactions. 

The combination of electrical properties with good mechanical performance is of particular interest in electroactive pol5mieric technology. Fibers have an intrinsically high structure factor, which results in lower percolation threshold values, avoiding material fracture with low filler content Also, the use of mechanically stronger fibers will result in stronger composites. 

Recently, PVDF has been intensively studied by many authors as a polymer matrix for ceramic nanopowders such as BaTiOs [212,214-216], PbTiOs [217], CaCOs [218], and Pb(Zro.5TiOo.5)03 [215] because they combine the excellent ferroelectric properties of ceramics with the flexible mechanical properties of the polymer. The PVDF polymer composites with electroactive ceramic nanoparticles were prepared by sol-gel processes [214,217], a natural adsorption action between the nanosized BaTiOs and PVDF particles, and then a hot press process [216]. 

Carbon nanotubes are synthesized using metal catalysts, which are later difficult to remove fiom the nanotubes to assure high purity. These impurities develop pseudocapacitive properties of CNT-based actuators. The trend in carbon-based actuators is to find alternatives to CNTs, especially to SWCNTs, mostly because of their high cost. CNTs have still unique properties and by far better electrical conductivity compared to amorphous carbons, and rather than replacing, the combination of CNTs with different types of amorphous carbons in electroactive carbon-polymer composite actuators is the prospect. 

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