Synthesis and electrochromic properties of aromatic polyetherimides based on a triphenylamine-dietheramine monomer

A Piezoelectric-Driven Electrochromic/Electrofluorochromic Dual-Modal Display Device

Electrochromic (EC) reflective displays offer great advantages in delivering information and providing visual data, but are limited in dark environments. Reflective/emissive dual-modal displays capable of electrochemically-induced color and fluorescence change simultaneously are highly desirable, especially possessing rapid response speed as well as long-term durability. Herein, an electroactive fluorescent ionic liquid based on triphenylamine and imidazole (EFIL-TPA) has been synthesized for reflective/emissive dual-modal display. The resultant device exhibits outstanding electrochromic/electrofluorochromic (EC/EFC) performance with low driving voltage (below 1.0 V), fast switching speed (0.57-1.8 s), and remarkable cycling durability (91% retention for 10 000 cycles). A piezoelectric nanogenerator (PENG) driven EC/EFC integrated system is fabricated to harvest energy from human motion and visually drive the color/fluorescence change for human motion indication in both bright and dark environments. This innovative EC/EFC dual-modal display device based on EFIL-TPA supports a huge space for the development of self-powered human motion visualized indication in all-light conditions.

Novel polyimides containing flexible carbazole blocks with electrochromic and electrofluorescencechromic properties

A series of polyimides (PIs) were prepared by polycondensation of a diamine monomer with five anhydrides (1,2,4,5-benzenetetracarboxylic anhydride (BTA), 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTD), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BTD), 4-[(1,3-dihydro-1,3-dioxo-5-isobenzofuranyl)oxy]-1,3-isobenzofurandione (DDII), and 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BPTD)), which have anodic electrochromic (EC) properties. These PIs not only show good solubility and thermal stability, but also demonstrate stable electrochemical oxidation behavior and good EC properties, and the highest retained electroactivity reaches 99% after 600 cycles. In addition, the series of PIs exhibit excellent electrofluorescencechromic (EFC) properties. Therefore, the novel materials will contribute to the application of EC or EFC displays in the future.

A comparative study of redox-active, ambipolar electrochromic triphenylamine-based polyimides prepared by electrochemical polymerization and conventional polycondensation methods

The spectroscopic, electrochemical and electrochromic properties of polyimides with tetraphenylbenzidine (TPB) units prepared by electropolymerization and polycondensation were compared.

Synthesis and Electrochromism of Highly Organosoluble Polyamides and Polyimides with Bulky Trityl-Substituted Triphenylamine Units

Two series of polyamides and polyimides containing bulky trityl-substituted triphenylamine units were synthesized from condensation reactions of 4,4′-diamino-4′′-trityltriphenylamine with various dicarboxylic acids and tetracarboxylic dianhydrides, respectively. The polymers showed good solubility and film-forming ability. Flexible or robust films could be readily obtained via solution-casting. The use of aliphatic diacid or dianhydride reduces interchain charge transfer complexing and leads to colorless polyamide and polyimide films. These polymers showed glass-transition temperatures in the range of 206–336 °C. Cyclic voltammograms of the polyamide and polyimide films displayed reversible electrochemical oxidation processes in the range of 0–1.0 or 0–1.3 V. Upon oxidation, the color of polymer films changes from colorless to blue-green or blue. As compared to the polyimide counterparts, the polyamides showed lower oxidation potentials and thus a higher electrochromic stability and coloration efficiency. Simple electrochromic devices were also fabricated as a preliminary investigation for electrochromic applications of the prepared polymers.

Novel organosoluble polyarylates based on diphenylamine-fluorene units

Two kinds of polyarylates with diphenylamine-fluorene units were synthesized from the bisphenol monomer “ N, N-di(4-hydroxyphenyl)-2-amino-9,9-dimethylfluorene” with two different benzenedicarbonyl chlorides. These polyarylates were highly soluble in N, N-dimethylacetamide, tetrahydrofuran, and chloroform and could be easily solution-cast into transparent films. Both of the polyarylates exhibited a couple of reversible redox with half-wave potentials in the range of 0.87–0.90 V. During the electrochromic process, the color of the film changed from colorless (neutral state) to grey green (oxidation state) with a high coloration efficiency of 242 cm2 C−1. Compared with the polyarylates prepared from terephthaloyl chloride, the polyarylates prepared from isophthaloyl chloride exhibited enhanced fluorescence because of the reduced charge-transfer effect. Furthermore, its fluorescence could be reversibly switched under the applied potentials.

Synthesis and properties of electroactive aromatic polyimides with methyl- or trifluoromethyl-protecting triphenylamine units

Two series of new redox-active aromatic polyimides with methyl- (–CH3) or trifluoromethyl (–CF3)-protecting triphenylamine moieties were prepared from 4,4′-diamino-4″-methyltriphenylamine and 4,4′-diamino-4″-(trifluoromethyl)triphenylamine with aromatic tetracarboxylic dianhydrides via the conventional two-step polycondensation technique. Flexible and strong polyimide films could be obtained via the thermal curing of their precursor poly(amic acid) films or direct solution cast from some organosoluble polyimides. The polyimides showed high glass-transition temperatures between 269°C and 312°C, and they did not show significant decomposition before 500°C in air or under nitrogen atmosphere. Cyclic voltammograms of the polyimide films on the indium–tin oxide-coated glass substrate exhibited a pair of reversible redox waves with half-wave oxidation potentials of 1.08–1.10 V (for the –CH3 series) and 1.23–1.26 V (vs. silver/silver chloride; for the –CF3 series) in acetonitrile solution. The polyimide films showed anodic electrochromism from pale yellow neutral state to purplish blue (for the –CH3 series) and chrome yellow (for the –CF3 series) when oxidized.

Synthesis and electrochemical properties of new redox-active polyimides with (1-piperidinyl)triphenylamine moieties

A series of new electroactive aromatic polyimides with (1-piperidinyl)triphenylamine moieties were prepared from 4,4′-diamino-4″-(1-piperidinyl)triphenylamine and aromatic tetracarboxylic dianhydrides via the conventional two-step polycondensation technique. Flexible and strong polyimide films could be obtained via the thermal curing of their precursor poly(amic acid) films. The polyimides showed high glass transition temperatures between 288°C and 318°C, and they did not show significant decomposition before 500°C in air or nitrogen atmosphere. Cyclic voltammograms of the polyimide films on the indium–tin oxide-coated glass substrate exhibited a pair of reversible oxidation waves with low onset oxidation potentials of 0.45–0.49 V (vs. silver/silver chloride) in acetonitrile solution. Upon oxidation, the color of the polyimide films changes from pale yellow to yellowish green and finally to blue.

Design of triphenylamine appended anthracene derivatives: electro-polymerization and their electro-chromic behaviour

Three derivatives of anthracene as a core interior with terminal one or two triphenylamine sides have been designed and developed to achieve a smart metal free electrochromic materials.

Electrochemically fabricated electrochromic films from 4-(N-carbazolyl)triphenylamine and its dimethoxy derivative

4-(N-Carbazolyl)triphenylamine (TPACz) and its methoxy derivative MeOTPACz could be facilely fabricated into redox-active and electrochromic PTPACz polymer and (MeOTPACz)2 dimer films via electrochemical polymerization.

Electrochemical synthesis of electrochromic polycarbazole films from N-phenyl-3,6-bis(N-carbazolyl)carbazoles

Electroactive and electrochromic polycarbazole films were directly prepared on electrodes from N-phenyl-3,6-bis(N-carbazolyl)carbazoles by carbazole-based electrochemical oxidative coupling.

Electrosynthesis and electrochromic properties of poly(amide-triarylamine)s containing triptycene units

Redox-active and electrochromic films of poly(amide-triarylamine)s with triptycene units have been directly fabricated on the electrode surface via the electrochemical oxidative coupling of triphenylamine or carbazole units.

Facile preparation of electrochromic poly(amine–imide) films from diimide compounds with terminal triphenylamino groups via electrochemical oxidative coupling reactions

Electroactive and electrochromic poly(amine–imide) films could be directly prepared on electrodes from diimide compounds TPA6F-DI and TPASO2-DI with triphenylamino end groups by electrochemical oxidative coupling.