Highly soluble polyimide bearing bulky pendant diphenylamine-pyrene for fast-response electrochromic and electrofluorochromic applications

Dual-Switching Electrochromism and Electrofluorochromism Derived from Diphenylamine-Based Polyamides with Spirobifluorene/Pyrene as Bridged Fluorescence Units

“…The superior EFC switching stability of S-HPA was ascribed to the stronger electronic resonance and lower oxidation potential. Compared with most materials reported in the literature that only exhibited moderate stability after a few tens of cycles, ,,− the remarkable EFC cyclic stability of the two polyamides that stemmed from the electronic coupling between the two nitrogen centers will greatly improve the real-life applications of EFC materials.…”

“…Triphenylamine (TPA) derivatives are developing vibrantly on account of their excellent photoactive/electroactive properties and have been extensively used in hole-transporters, organic light-emitting diodes, and electrochromic (EC) materials. − TPA with para-position methoxy protection can be easily switched between the neutral state and the oxidation state of cation radicals, making it an ideal moiety for EC materials. , In addition, TPA-based MV systems were also well developed and demonstrated for highly stable EC materials. , However, most TPA-based materials exhibited low fluorescence contrast because of the weak fluorescence of TPA, , which largely restricted the real-life applications of EFC devices. To circumvent this problem, incorporation of other fluorophores into TPA-based MV systems is a useful approach to enhance the fluorescence of the resulting materials. , Furthermore, when the fluorophore is fabricated as a π-conjugated bridge to link the TPA unit, not only the fluorescence contrast can be greatly improved but also the switching stability benefiting from the resonance stability of the conjugated TPA system can be maintained. , Spirobifluorene and pyrene are two typical fluorophores, which have been widely used in various fluorescence sensors, solar cells, and organic photovoltaic cells. − Because of their strong fluorescence and good electron delocalization properties, spirobifluorene and pyrene will be promising bridging units in the TPA-based MV systems to synergistically improve the fluorescence contrast and EC/EFC cyclic stability.…”

Synthesis and characterization of melt‐processable polyimides derived from diaminodiphenylsulfone and benzophenone tetracarboxylic dianhydride with excellent heat resistance and thermoplasticity

“…It is well known that via adding a third monomer containing flexible segments, bulky groups and non-coplanar structures during copolymerization, these structures can be incorporated into the molecular chain of polyimides, thereby effectively improving their solubility and processability. [19][20][21][22][23] In the late 1970s, the Langley Research Center of NASA introduced thermoplastic polyimide under the name ''LARC-TPI''. 24,25 Since then, thermoplastic polyimides have attracted extensive research attention.…”

“…To overcome these problems, different structural modifications were carried out to improve the solubility and processing characteristics of aromatic polyimides. It is well known that via adding a third monomer containing flexible segments, bulky groups and non‐coplanar structures during copolymerization, these structures can be incorporated into the molecular chain of polyimides, thereby effectively improving their solubility and processability 19–23 . In the late 1970s, the Langley Research Center of NASA introduced thermoplastic polyimide under the name ''LARC‐TPI'' 24,25 .…”

Synthesis and characterization of triarylamine‐based polyimides for electrochromic and optoelectronic conversion behaviors

“…introduced the non‐coplanar twist structure, which resulted in improved solubility of the PI . Zhao's group designed and developed fluorescent/electroactive polyimide by introducing diphenylamine‐pyrene unit, which resulted in high solubility and high potential for use as the multifunctional displays . Moreover, Zhang and coworkers reported a kind of polyimide containing benzothiadiazole as the donor unit and 4,4′‐bisphenol A dianhydride as the acceptor unit, which possessed effective photoluminescence, resistive switching characteristics and electroluminescence properties .…”