General Platform for Remarkably Thermoresponsive Fluorescent Polymers with Memory Function.

Memory polymers capable of remembering their shape or thermal history have attracted increasing interest due to their potential applications in smart and medical devices. Memory polymers established are mechanically based, which suffer from some inherent limitations such as low sensitivity and bulky size. Here, we develop a general platform for sensitive memory polymers. Incorporating crystallizable polymers with solid-state fluorescent dyes results in crystallizable fluorescent polymers. Such polymers show remarkably temperature-dependent fluorescence emission. Interestingly, fluorescence of the polymers shows a hysteresis between heating and subsequent cooling scans, which offers them a valuable thermally stimulated recording function. Both off-on and on-off recording functions can be achieved. Characters recorded on the polymer films can be erased and rewritten. Moreover, thermal history subjected to the polymers can be memorized and retrieved by measuring fluorescence intensity. With the merit of easy synthesis, recording function, remarkably thermoresponsive fluorescence with memory function, superior flexibility, and biocompatibility inherited from polymers, crystallizable fluorescent polymers offer a general platform for memory fluorescent polymers that are potentially useful for biosensing, recording materials, and smart devices.