The design, fabrication and characterization of a new shape memory polymer (SMP) with built-in temperature sensing capabilities are reported. The material was prepared by incorporating a fluorescent, chromogenic oligo(p-phenylene vinylene) dye into a cross-linked poly(cyclooctene) (PCO) matrix via guest diffusion. The dye concentration was chosen to allow for self-assembly of the dye upon drying, resulting in the formation of excimers. Exposure of these phase-separated blends to temperatures above the melting point (Tm) of the PCO leads to dissolution of the dye molecules, and therefore causes a pronounced change of their absorption and fluorescence color. The optical changes are reversible; i.e., the aggregate absorption and emission are restored upon cooling below Tm. The color is dictated by the phase behavior and is independent of the mechanical state of the SMP. Thus the effect allows one to monitor reaching of the set/release temperature of the polymer.
ASJC Scopus subject areas
- Materials Chemistry