Ionic polymer-metal composite properties

TABLE 16.2 Comparison between Two Mechanical Properties of Different Actuating Materials Skeletal Muscles, Thermomechanical (Thermal Liquid Crystals and Thermal Shape Memory Alloys), Electrochemomechanical (Conducting Polymers and Carbon Nanotubes) and Electromechanical (Ionic Polymer Metal Composites, Field Driven Liquid Crystal Elastomers, Dielectric Elastomers)... 

Additionally, different additives were studied to enhance the actuation characteristics of ionic polymer-metal composites. Multiwalled carbon nanotubes (M-CNT) were incorporated in the polymer matrix to improve mechanical properties and electrical conductivity. The tests indeed showed... 

Nemat-Nasser, S., Zamani, S. and Tor, Y. (2006). Effect of solvents on the chemical and physical properties of ionic polymer-metal composites. Journal of Applied Physics 99, 10, p. 104902. 

The forth direction, analytical modeling for understanding the behaviors of these materials, has been popular approach. Testing and characterization have been conducted for developing the models. Such attempts have been done especially for ionic polymer metal composites (IPMCs)[58, 70, 72, 120]. Nemab Nasser and his co-workers carried out extensive experimental studies on both Nafion- and Flemion-based IPMCs consisting of a thin perfluorinated ionomer in various cation forms, seeking to imderstand the fundamental properties of these composites, to explore the mechanism of their actuation, and finally, to optimize their performance for various potential applications[121]. They also performed a systematic experimental evaluation of the mechanical response of both metal-plated and bare Nafion and Flemion in various cation forms and various water saturation levels. They attempted to identify potential micromechanisms responsible for the observed electromechanical behavior of these materials, model them, and compare the model results with experimental data[122]. A computational micromechanics model has been developed to model the initial fast electromechanical response in these ionomeric materials[123]. A number... 

Table 9.1 Performance properties of typical IPMCs (Reproduced with permission from IS. Park, K. M. Jung, D. Kim, et al. Physical principles of Ionic polymer-metal composites as electroactive actuators and sensors, MRS Bulletin, 33, 3, 190-5. Copyright (2008) MRS)...

Panwar V, Lee C, Ko SY et al (2012) Dynamic mechanical, electrical, and actuation properties of ionic polymer metal composites using PVDF/PVP/PSSA blend membranes. Mater Chem Phys 135 928-937... 

Yeo RS, Yeager HL (1985) Structural and transport properties of perfluorinated ion-exchange membranes. Modem Aspect of Electrochem 16 437-505 Zhu Z, Asaka K, Chang L et al (2013a) Multiphysics of ionic polymer-metal composite actuator. J Appl Phys 114, 084902... 

Kikuchi K, Tsuchitani S (2009) Effects of environmental humidity on electrical properties of ionic polymer-metal composite with ionic liquid. In Proceedings of the ICCAS-SICE 2009, IEEE, Fukuoka, pp 4747 751... 

Ionic Polymer-Metal Composites or IPMCs, are one type of electroactive polymers that display remarkable shape-altering properties. Most IPMCs are made up of a polymer membrane contained within metal electrodes, which are typically gold or platinum. When an IPMC is hydrated, counter-ions can move freely away from stationary anions toward an electrode when an electric current is induced. This is due to the hydrating liquid s effect of solvating the cation. The result is the IPMC s deflection toward the anode. IPMC membranes have advantages over traditional actuators in the fact that they lack moving parts and require very small voltages to operate. 

When the mesogen moiety is included into the main chain of the polymer, the obtained macromolecule contains inherently rigid units, which usually result in remarkable mechanical properties and thermal stability. Fibers made by these polymers compete with the best ceramic fibers and are far superior to metal fibers [83]. They therefore are ideal candidates as reinforcements for polymer-based composites. However, these materials often have a poor miscibility and adhesion to other polymeric substrates, limiting the range of their applications. This problem basically arises from weak intermolecular interactions either within the liquid-crystalline polymer itself or with the matrix of the composite. Strong ionic... 

A polymer electrolyte with acceptable conductivity, mechanical properties and electrochemical stability has yet to be developed and commercialized on a large scale. The main issues which are still to be resolved for a completely successful operation of these materials are the reactivity of their interface with the lithium metal electrode and the decay of their conductivity at temperatures below 70 °C. Croce et al. found an effective approach for reaching both of these goals by dispersing low particle size ceramic powders in the polymer electrolyte bulk. They claimed that this new nanocomposite polymer electrolytes had a very stable lithium electrode interface and an enhanced ionic conductivity at low temperature. combined with good mechanical properties. Fan et al. has also developed a new type of composite electrolyte by dispersing fumed silica into low to moderate molecular weight PEO. 

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