Multi‐Stimuli Responsive Thiazolothiazole Viologen‐Containing Poly(2‐Isopropyl‐2‐Oxazoline) and Its Multi‐Modal Thermochromism, Photochromism, Electrochromism, and Solvatofluorochromism Applications

Abstract

Smart materials are highly desirable over the recent decade due to the growing demand on complicated nature. Smart materials with stable stimuli‐responsive properties are widely applied in sensors, smart windows, displays, and chemical valves, but they are relatively rare. Most of the current chromic materials are triggered by one or two external stimuli, and only a few multi‐stimuli responsive instances still suffer by their restricting functional states, such as solution or polymer. To address these challenges, researchers are focusing their efforts on developing a new generation of multi‐stimulus responsive chromic materials. In this article, our group has adopted a new strategy for the synthesis of the multi‐stimuli responsive single polymeric material, which can be useful for different applications (such as thermochromism, photochromism, electrochromism, and solvatofluorochromism). Thiazolothiazole viologen (TTv)‐containing poly(2‐isopropyl‐2‐oxazoline) (PiPO) was synthesized using a one‐pot reaction where the living cationic polymer chains were reacted with thiazolothiazole viologen to produce multi‐stimuli responsive PiPO‐TTv. PiPO‐TTv‐based device demonstrated multi‐responsive properties due to the thermoresponsive properties of PiPO segments and photo‐, electro‐responsive properties of TTv monomer, respectively. PiPO‐TTv material, additionally exhibits fluorescence characteristics that makes it appealing for environmental and molecular biological sensor applications.

A Multistimuli-Responsive Cd-MOF Constructed by an Extended Viologen-Based Carboxylate Ligand

“…The original state shows strong absorption bands below 450 nm, while under the irradiation of UV–vis light, two absorption peaks appear at 620 and 730 nm, respectively. Moreover, the intensity of absorption peaks becomes strong with the increasing of illumination time, which is similar to the reported viologen-based complexes. , …”

“…Moreover, the intensity of absorption peaks becomes strong with the increasing of illumination time, which is similar to the reported viologen-based complexes. 29,30 Additionally, to further determine the mechanism of discoloration, the ESR spectrum was tested (Figure 4c). The ESR measurement of yellow powder has no signal before irradiation, but a sharp single peak was detected at g = 2.0049 after irradiation.…”

Thermochromism of rapid responses to temperature changes versus mechanochromism in a Ni-dithiolene complex salt

“…In theory, materials that exhibit temperature-dependent structures are promising candidates for designing thermochromic materials. Although thermochromism has been observed in a wide range of materials, including inorganics, 7 organics, 3 polymers/polymeric composites, 12,13 and hybrids, 14 designing and discovering new thermochromic materials systems remain a challenge at present. It is noteworthy that thermochromism has been infrequently explored for metal-dithiolene complexes so far, 15 although they show the possibility of thermochromism, and moreover, hold several advantages, including multiple spectral bands ranging from ultraviolet to near-infrared spectral regions, which originate from the electron transitions of π → π and MLCT/LMCT within a metal-dithiolene complex anion together with ion-pair charge transfer transition (IPCT), respectively.…”

Phase‐Changing Sodium Carboxymethylcellulose‐As An Electrolyte for Electro‐Thermochromic Smart Window with Synergistic Optical Modulation

“…However, there is a heightened demand for multi-stimuli-responsive smart windows that could be attributed to their wide array of applications in terms of utility and operational capabilities. [39,40] Kim et al, presented a noteworthy development in the form of a VO 2 /WO 3 hybrid smart window, in which WO 3 -based electrochromic and VO 2 -based thermochromic cells were incorporated into a single device. [41] While these reported materials may exhibit considerable promise, it's important to note that their phase transition temperatures are relatively too high for practical applications.…”