Incorporation of small amounts (3-7 wt%) of nanoparticles such as layered silicate (MMT), silica, and carbon nanotube (CNT) may greatly alter important mechanical and electrical properties of NafionTM matrix. These fillers can be easily modified and functionalized to implement unique properties of IPMC. Our recent study indicates that Nafion/MMT, Nafion/silicates composites can be prepared with nano-scale dispersion. Most of IPMCs based on Nafion nanocomposite exhibit improved displacements and blocking forces compared to pure NafionTM based IPMC. Due to the barrier property and hygroscopic nature of silicates, water loss of IPMC under dc voltage is greatly reduced, which prolong the service life of IPMC. In the case of Nafion / layered silicate nanocomposite, however, response is slow due to the barrier effect of the clay platelet; while in Nafion / silica and Nafion / CNT systems, response rate is comparable with that of conventional IPMC. Improvement in mechanical properties and relaxation was achieved without any significant loss of important properties.
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