Simultaneous Microscopic Structure Characteristics of Shape-Memory Effects of Thermo-Responsive Poly(vinylidene fluoride-co-hexafluoropropylene) Inverse Opals.

This paper presents a simultaneous microscopic structure characteristic of shape-memory (SM) poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) inverse opals together with a bulk PVDF-HFP by scanning electron microscopy (SEM). The materials show a thermo-sensitive micro-SM property, accompanied with a reversible and modulated optical property. The introduction of the inverse opal structure into the shape-memory polymer material renders a recognition ability of the microstructure change aroused from complex environmental signals by an optical signal, which can be simultaneously detected by SEM. Furthermore, this feature was applied as a reversible write/erase of fingerprint pattern through the press-stimulus and solvent-induced effect, together with the changes of morphology/optical signal. This micro-SM property can be attributed to the shrink/swell effect of the polymer chain from external stimuli combined with the microscopic structure of inverse opals. It will trigger a promising way toward designing reversible micro-deformed actuators.