Patterned fluorescence films with reversible thermal response based on the host–guest superarchitecture

Abstract

This paper reports patterned films with thermal colorimetric and fluorescent response fabricated by a combined approach based on electrophoretic deposition (EPD)–photolithography. A composite film of diacetylene (DA)/layered double hydroxide (LDH) was prepared by the method of EPD, and the photolithography technique was subsequently employed to further obtain a polydiacetylene (PDA)/LDH patterned fluorescence film via UV-induced polymerization of DA in the two-dimensional (2D) gallery of LDH matrix. The PDA/LDH film shows a well c-orientation of LDH platelets (the ab plane of the LDH platelets parallel to the substrate) confirmed by XRD and SEM. Both the in situUV-vis absorption and fluorescence emission spectroscopy indicate that the composite film exhibits marked thermal colorimetric and fluorescent behavior in the temperature range 20–130 °C, which is reversible over a number of heating/cooling cycles. It should be noted that the pristine PDA shows no reversible thermal colorimetric and fluorescent performance at all. The transformation of an organic chromophore from irreversible to reversible thermal response material upon incorporation into a 2D layered matrix is the most distinct feature in this work. It was demonstrated that the thermally response behavior resulted from the strong hydrogen bond interaction between the PDA and LDH matrix, which was confirmed by in situ Raman and in situ attenuated total reflection Fourier-transform infrared (ATR FT-IR) spectroscopy. Therefore, this work provides new opportunities for the fabrication of thermally responsive patterned films with high stability and reversibility, which can be used in intelligent response and display devices.