A Brief Review on Advances in Rhodamine B Based Chromic Materials and Their Prospects

Chromic (stimuli-responsive reversible color change in the visible region) materials have been used in a number of commercial outlets with increasing demands. It is an important scientific issue and research hot spot in recent years simply due to its huge prospects. It includes the following: (i) photochromics in sunglasses, probes, optical data storage, molecular logic-gate and keypad lock, photopatterning, and photoprinting; (ii) thermochromics in paints, inks, architecture, molecular thermometers, and cotton fabrics; (iii) mechnochromics in plastics, textiles, and anticounterfeiting systems; (iv) electrochromics in switchable glass, smart paper strips, and flexible electronics; (v) halochromics in digital image colorimetry and acid–base indicators; (vi) ionochromics in colorimetric sensors and complexometric indicators; and (vii) hydrochromics in water-jet printing. The well-known rhodamine B (RhB) dye has now been considered a unique stimuli-dependent chromic material by researchers because of its outstanding photophysical and physicochemical properties that are suitable for real applications. In this review work, almost all of the works published on RhB-based stimuli-responsive materials from 1977 to 2022 have been studied critically, and significant progress is arranged in chronological order. In addition, an attempt has been made to show the prospects of what they can do in human service in the near future.