Journal of Polymer Science Part B: Polymer Physics, Vol.56, No.1, 46-52, 2018
Thermal actuation of hydrogels from PNIPAm, alginate, and carbon nanofibres
Composite ionic-covalent entanglement (ICE) hydrogel networks were prepared from poly(N-isopropylacrylamide), alginate, and carbon nanofibres. An optimised triple network hydrogel with 86% water content exhibited a compressive strength of 3.0 +/- 0.1 MPa and 66 +/- 13 mS/cm electrical conductivity. Thermal actuation was shown to have a shorter response time for gels containing nanofibres, compared to those which did not and hydrogel samples more than halved in volume within 1 minute when placed in a 60 degrees C water bath. Controlled dye release was demonstrated as a potential application and used to further quantify thermal actuation over short times. Joule heating techniques were used to electronically actuate the hydrogel samples, removing the traditional requirements for immersion in a temperature controlled liquid. It is expected that devices based on these materials will find potential applications in soft robotics and micro fluidics. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 46-52
Keywords:carbon nanofibres;composite hydrogel;hydrogel;ionic-covalent entanglement;thermal actuation