Polyvinylidene fluoride grafted poly(styrene sulfonic acid) as ionic polymer-metal composite actuator

• Published in: Sensors and actuators. A. Physical. Vol. 279; pp. 157 - 167
• Main Authors: Mehraeen, Shayan, Sadeghi, Sahl, Cebeci, Fevzi Çakmak, Papila, Melih, Alkan Gürsel, Selmiye
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.08.2018; Elsevier BV
• Subjects: Actuation; Actuators; Bending actuator; Conductivity; Electroless plating; Fluorides; Functional groups; Grafting; Ion exchange; IPMC; Membranes; Morphology; Poly(styrene sulfonic acid); Poly(vinylidene fluoride); Polymerization; Polystyrene; Polystyrene resins; Polyvinylidene fluorides; Proton exchange membrane fuel cells; Protons; PVDF-g-PSSA; Radiation induced graft polymerization; Sensors; Styrenes; Sulfonic acid; Poly(styrene sulfonic acid); Poly(vinylidene fluoride); PVDF-g-PSSA; Radiation induced graft polymerization; Bending actuator; IPMC
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2018.05.038

[Display omitted] •PVDF-g-PSSA was demonstrated as an IPMC actuator for the first time in literature.•Synthesis of PVDF-g-PSSA was performed by a novel, simple and fast method.•High water uptake and ion exchange capacity of grafted membrane were obtained due to porous microstructure.•Best actuation performance of IPMC actuator was achieved with 35 wt.% graft level.•A cheaper alternative to traditional Nafion-based IPMC was developed. A high performance ionic polymer-metal composite actuator (IPMC) based on proton conductivity of poly(styrene sulfonic acid) was fabricated using a simple and novel method. Poly(styrene sulfonic acid) (PSSA) as a well-known hydrophilic proton conductive functional group was radiation grafted on polyvinylidene fluoride (PVDF) at different graft levels. The material system is well known for the proton exchange membranes of fuel cells, however, its IPMC application is novel. Flexible, soft and porous membranes were prepared by simple solution casting technique. Physical, mechanical, thermal and actuation properties of prepared membranes were characterized and compared with Nafion®. The membrane with highest graft level showed comparable ion exchange capacity and proton conductivity with that of Nafion whereas its water uptake is near three-fold greater than Nafion. To make PVDF-g-PSSA based IPMC actuators, Pt particles were deposited on both sides of the membranes using electroless plating method. Actuation performance of the IPMC actuators under various AC potentials and different frequencies were investigated in air. The results revealed that the PVDF-g-PSSA membrane with highest graft level showed highest average bending strain at 0.1 Hz and 4 V. The enhanced bending actuation behavior was attributed to porous morphology and large water uptake of graft polymerized actuators. Compared with traditional Nafion-based IPMC, our bending actuator is cheaper, and its preparation is fast and simple. So, it can be a viable replacement candidate for the traditional Nafion in soft actuator systems.