Reversibly Thermochromic, Fluorescent Ultrathin Films with a Supramolecular Architecture

摘要

Tunable luminescent materials that respond to different external stimuli have attracted great attention during the last few years, owing to their potential applications in fluorescent switches, sensors, and optical recording devices. Mechanisms responsible for the change in luminescence include chemical reactions and alteration of the molecular packing mode. Since solid-state chemical reactions frequently have low conversion efficiency, recent attention has focused on controlling and tuning the molecular packing mode as a strategy for the design and preparation of intelligent luminescent materials. To date, although several types of responsive luminescent materials have been developed (e.g., piezochromic, deformation-induced chromic, photochromic, thermochromic,and humidity-related colorimetric luminescent systems), challenges remain. For instance, to meet the requirements of luminescent devices or sensors, it is important to be able to assemble ordered thin films with regular molecular orientation and intermolecular packing mode on two-dimensional surfaces. Switching of solid-state luminescence based on such ordered thin films is rather rare, however. Therefore, it is of crucial importance to develop new ways to fabricate ordered film systems with fluorescent properties which respond to environmental stimuli. Furthermore, fast response, facile reversibility, and stable repeatability are all necessary from the viewpoint of practical application of such materials in sensors. Therefore, there is an urgent demand to develop new types of solid-state responsive materials as well as sensors with high efficiency, stability, and reproducibility.