Triblock Copolymer Organogels as High-Performance Dielectric Elastomers

Abstract

Block copolymers and nanostructured materials derived therefrom are becoming increasingly ubiquitous in a wide variety of (nano)technologies. Recently, we have demonstrated that triblock copolymer organogels composed of physically cross-linked copolymer networks swollen with a midblock-selective solvent exhibit excellent electromechanical behavior as dielectric elastomers. In-plane actuation of such organogels, collectively referred to as electroactive nanostructured polymers (ENPs) to reflect the existence of a self-organized copolymer morphology, is attributed to the development of an electric-field-induced surface-normal Maxwell stress. In this study, we examine the composition and molecular weight dependence of the electromechanical properties afforded by organogels prepared from poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) triblock copolymers selectively swollen with EB-compatible aliphatic oligomers. These materials undergo ultrahigh actuation displacement at significantly reduced electric fields relative to previously reported dielectric elastomers and possess electromechanical coupling efficiencies, which relate the conversion from electrical input to mechanical output, greater than 90%. The design of ENPs with broadly tunable electromechanical properties represents an attractive route to responsive materials for advanced engineering, biomimetic and biomedical applications.

Fast low-voltage electroactive actuators using nanostructured polymer electrolytes

“…In particular, ionic polymer actuators, which are a category of electroactive actuators, comprising a layer of polymer electrolyte sandwiched in between electrodes have emerged as promising candidates in such applications, owing to their lightweight, flexibility, mechanical robustness and ease of fabrication at low cost [5][6][7] .…”

“…In fact, research on actuators comprising ionic liquids has commonly used a few conventional polymers 25,26 , thus impeding major advances in ionic polymer actuators, which essentially require the optimization of ion transport characteristics and mechanical properties of the polymer layer. In this respect, the use of microphase-separated polymers in actuators has recently been proposed as a promising means to elevate the actuator performance 7,10,[33][34][35][36][37][38][39][40][41] . For instance, Long et al 34,35 , Spontak et al 7,36,37 , Colby et al 38,39 and Watanabe et al 10,40 , have employed self-assembled block copolymers in actuators and improved electromechanical deformation has been reported, compared with that of several conventional polymers lacking organization.…”

Electroactive Thermoplastic Dielectric Elastomers as a New Generation Polymer Actuators

“…However, electroactive thermoplastic dielectric elastomer, sometimes referred to as electroactive nanostructured polymers (ENP), is a quite new terminology in the field of electroactive polymers (Chmidt et al, 2008;Jang et al, 2011;Kim et al 2010Kim et al , 2011Shankar et al, 2007aShankar et al, , 2007bShankar et al, , 2007cShankar et al, , 2008Vargantwar, 2011). Thus, this book www.intechopen.com will focus on demonstrating unique electric actuation properties of the thermoplastic dielectric elastomers.…”

Deviation from time-composition equivalence in polymer solutions with selective cosolvents

“…10 While such morphologies elucidate the principal factors responsible for molecular self-assembly, they are likewise beneficial in various (nano)technologies. 11 These soft nanostructures, as well as their stability and thermo/(electro)mechanical properties, 12 can be fine-tuned or grossly altered through the physical incorporation of one or more solvents, 13 (co)polymers 14 or nanoparticles. 15 In the present study, the A endblocks of each ABA triblock a Author to whom correspondence should be addressed.…”

“…1(a). At low ω, the material behaves as a swollen elastomer and, following stretch and release, abruptly snaps back to its original size (with little hysteresis upon repeated cycling) 12 due to the elasticity of the copolymer network. At high ω beyond the crossover point, however, this ternary solution displays evidence of hindered recovery and considerable viscous dissipation after it is stretched and released.…”