Stretching of Polydomain and Monodomain Nematic Elastomers: Experimental Study
Seminar Room 1, Newton Institute
We review our experimental studies on the stretching driven director-rotation of polydomain nematic elastomers (PNEs) and monodomain NEs (MNEs). The texture of PNEs primarily depends on the preparation state, i.e., whether the cross-links are introduced in the high-temperature isotropic or low-temperature nematic state. The director in the isotropic-genesis PNEs can be rotated at unusually low energy cost by external fields. As a result, the isotropic-genesis PNEs can be largely deformed at small tensile force and moderate electric field strength. In contrast, the nematic genesis PNEs do not show such soft response due to the memory of the initial random director configuration. We observe the remanent of the initial director configuration even in the highly stretched state. The formation of stripe patterns has been known as a typical phenomenon of mechanical instability for the MNEs stretched normally to the initial global director. We introduce a different type of mechanical instability observed in our recent experiments for monodomain NEs.