Electromagnetic radiation driving of volume changes in nanocomposites made of a thermosensitive hydrogel polymerized around conducting polymer nanoparticles

S. BONGIOVANNI ABEL; C.R. RIVAROLA; C.A. BARBERO; M.A. MOLINA

RSC ADVANCES

ROYAL SOCIETY OF CHEMISTRY

Año: 2020 vol. 10 p. 9155 - 9164

Polymeric nanocomposites were obtained by the formation of a thermosensitive hydrogel matrix around conducting polymer (CP) nanoparticles. The CP is able to absorb electromagnetic radiation which is converted into heat and induce thephase transition of the surrounding hydrogel. The method chosen to form the hydrogel is the free radical polymerization of a copolymer (N-isopropylacrylamide (NIPAM) and 2-acrylamide-2-methylpropano sulfonic acid (AMPS), PNIPAM-co-2%AMPS) in the presence of bisacrylamide as the crosslinker. The nanoparticles are polypyrrole nanospheres (PPy NP), polyaniline nanofibers (PANI NF), and polyaniline nanospheres (PANI NP). The morphology of the composites was studied using SEM microscopy and the percentual composition of each material was evaluated by thermogravimetric analysis (TGA). The swelling equilibrium capacity and rate are clearly affected by the nanoparticle shape and nature. However, the nanocomposites LCST are similar to that of the matrix. Upon RF irradiation, the three nanocomposites increase the temperature and reach the LCST after 320 seconds of irradiation (320 kJ). Upon MW application, the local temperature reaches the LCST after only 30 sec (21 kJ), resulting in MW more effective than RF to drive the transition. These results demonstrate that the proposed materials are useful as a remotely drive actuator.