Towards softer thermo-reversible magnetogels

We report on softening strategies for thermo-reversible organoferrogels obtained by physical gelation of ferrofluids with gelators of the SEBS type (polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene triblock copolymers). The first approach investigates a mixture of tri- and diblock copolymers, where the diblock copolymer could act as a plasticizer. The second approach tests triblock copolymers with a longer middle block, in this case the concentration and size of the crosslinking PS micellar cores should be smaller. Rheological, mechanical, magnetic, and morphological properties of these systems were studied and compared with the first generation of physical organoferrogels. Notably with both approaches we achieved a decrease of the softening temperature. Such soft magnetic organogels are important for upcoming actuators due to their easy deformation in magnetic fields. (C) 2010 Published by Elsevier Ltd