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By using triphenylamine (TPA) with a propeller structure connected to the planar fluorene unit as monomer, three novel polyimide (PI)s were prepared through chemical imidization of N,N′‐(9,9‐bis(4‐(diphenylamino) phenyl)‐9H‐fluorene‐2,7‐diyl)‐bis(N‐(4‐methoxyphenyl) benzene‐1,4‐diamine) (TPAF‐NH2) with three kinds of dianhydrides. The three dimensional configurations are designed to decrease molecular stacking rising from strong imide bond, and for faster ion transport in cavity of PIs. All the three PIs have good performance of electrochromic(EC) and sensor. With the voltage increasing from 0 to 1.2 V, the color of P2 film changes from original yellow to red to blue with the response time of only 2.3 s (colored time [tc]) and 2.8 s (bleached time [tb]). The coloring efficiency (CE) of P2 reaches 310 cm2 C−1, with optical contrast (ΔT) of 54%. Especially, the electroactivity of P3 does not decrease significantly after 6000 s cycle. Additionally, there are dual‐band in near‐infrared (NIR) area after the PI being oxidized. P1 with photoluminescence (PL) quantum efficiency (φPL) of 48% can detect trinitrophenol (TNP) effectively. The novel PIs have promising prospect in NIR EC and TNP detection devices. [ABSTRACT FROM AUTHOR]

In this work, a series of multifunctional polyurethane (PU) materials containing three kinds of different triarylamine (TAA) units was prepared. These polymers show good solubility in common organic solvents and excellent thermal stability under a N2 atmosphere. The PU films show reversible color changes with high contrast ratios and electrochromic stability. Moreover, they have good memory storage performance. The ON/OFF current ratio is about two orders of magnitude. Meanwhile, they can be used as detectors for 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenol (TNP). The polymer solutions rapidly exhibit fluorescence-quenching phenomena when exposed to trace amounts of TNT and TNP. The PU films also have mechanical properties that make them suitable for use in stretchable devices. [ABSTRACT FROM AUTHOR]

A series of Schiff bases (SBs) were synthesized from 2-furancarboxaldehyde and different triphenylamine (TPA) derivatives to investigate the influence of substituted groups on the properties of SBs. The structures of SBs were characterized by means FTIR, NMR spectroscopy and elemental analysis (EA); the results showed an agreement with the proposed structure. The electrochemical, electrochromic and acidochromic properties of SBs were investigated by UV–vis spectroscopy and cyclic voltammetry (CV) techniques. The obtained SBs exhibited stable and reversible electrochromic properties. These anodic coloring films showed high coloration efficiency (CE). Furthermore, multiple reversible color states were also observed with the concentration changes of HCl vapor. [ABSTRACT FROM AUTHOR]

Abstract: A simple approach to obtain a series of polyamines (RPSBs) based on N,N′-bis(4-aminophenyl)-N,N′-bis(α-naphthyl)-bisphenylenediamine via reducing conjugated PolySchiff bases (PSBs) by NaBH4 is presented in this article. The structures and molecular weights of RPSB were characterized by means of FTIR, 1H NMR, and GPC which showed an agreement with the proposed ones. The RPSBs exhibited excellent solubility in many polar organic solvents, with inheriting good electrochromic characteristics. They displayed obvious absorption and fluorescence responses upon the addition of trifluoroacetic acid or HCl, with high sensitivity and specificity. The results of TGA and DSC show that the RPSBs are heat resistant and amorphous. The energy bands were calculated to be in the range of 2.09–2.55eV by using the cyclic voltammetry combined with the UV–vis spectra. The hybrid density functional theory (DFT) method was used to calculate the optimized geometry and electronic structure of RPSBs. SEM images show that the RPSBs were facile to self assemble into spherelike particles. [Copyright &y& Elsevier]

Highlights: [•] It is a simple approach to obtain polyimides by Michael addition reaction. [•] The prepolymers had excellent solubility in many common organic solvents. [•] The polyimides film revealed good thermal stabilities and electrochromic characteristics. [Copyright &y& Elsevier]

A novel series of triphenylamine (TPA)-contained polysiloxanes (PTPASi) have been synthesized by a normal reaction of hydrosilylation through poly(methylhydrosiloxane)(PMHS) with four TPA-based alkenes (TPAA) for electrochromic applications. Grafting TPA onto polysiloxanes was employed as a strategy to ameliorate the thermal stability and cycle stability of the electrochromic properties due to the enhanced force of adhesion between the polymer films and the ITO substrate. The morphology and impedance of the polymers after electro-oxidizing reaction was studied and didn’t reveal significant change suggesting good stability of the hybrid system. Meanwhile, with the introducing of the polysiloxane backbones, the four polymer films appeared nearly colorless in their natural state, in contrast to three primary colors of red, green and blue in their oxidized state. Hence, these PMHS films can be mixed to obtain all the other colors on the basis of the color mixing theory. In addition, the potential switching properties of the four polymers at the temperature of 150 °C have been investigated for the first time, which indicate high thermal stability and potential for relatively high temperature and/or long term cycling applications. [ABSTRACT FROM AUTHOR]

Two series of novel aromatic polyurethanes containing triphenylamine derivatives were synthesized via polycondensation of 4-(3,6-diisocyanato-9H-carbazol-9-yl) aniline, N,N-bis(4-isocyanatophenyl) benzene-1,4-diamine with various dihydroxy monomers such as phenolphthalein, 2,2-bis (4-hydroxyphenyl) -propane, 4,4'-dihydroxybiphenyl, 4, 4'-bishydroxy benzophenone and bisphenolfluorene, respectively. The variation of the backbone structure affected the electronic properties, solubility, molecular weight and thermal stability of polyurethanes. The thermal stability of polyurethanes was studied by the gravimetric analyzer. The electrochromic performance was investigated by cyclic voltammograms and spectroelectrochemical methods, which showed stable and reversible electrochromic properties. Besides, the color of polyurethanes can be varied from initial colorless to green then to blue via electro-oxidation, which indicates the polyurethanes will have potential applications for eletrochromic materials. In addition, the PUs exhibited memory characteristic. The result indicated the PUs could be applied in smart window and memory devices. [ABSTRACT FROM AUTHOR]

Ag nano-film was prepared on the glass substrate (GS) by vertical target pulsed laser deposition (VTPLD). Polyaniline (PANI) and polyaniline-graphene oxide (PANI-GO) composite suspension were obtained through chemical oxidative polymerization and in situ polymerization. GS/Ag nano-film/PANI and GS/Ag nano-film/PANI-GO composites were obtained by czochralski method. The structure, molecular weight, morphology and conductivity of samples were studied by IR, XRD, MALDI-TOF-MS, SEM, TEM and digital multimeter. Electrochemical and electrochromical properties of PANI and PANI-GO composites on GS/Ag nano-film were studied by CV and UV–vis DRS. Results show compact and uniform Ag nano-film with the particle size between 30 nm and 50 nm was prepared by VTPLD successfully and resistance values are between 1 Ω and 5 Ω, lower than that of ITO glass (20 Ω). PANI-GO composites on GS/Ag nano-film prepared under the optimal laser power of 17 W has lower color switching potential and wider shift range of characteristic peaks than PANI, especially GS/Ag nano-film/PANI-GO20 composites which has the color switching potential of 0.175 V and 0.557 V, and the characteristic peak shifts from 430 nm to 402 nm with the increasing potential from 0.2 V to 0.8 V. The obtained GS/Ag nano-film is a candidate for application as the electrode in the reflective electrochromic device. We can use less energy to make GS/Ag nano-film/PANI-GO20 composites switch color. [ABSTRACT FROM AUTHOR]

Abstract: A novel series of triphenylamine-containing aromatic polyurethanes (PUs) were synthesized via polymerization of N,N-bis (4-isocyanatophenyl) aniline monomer with different dihydroxy compounds. The structures of PUs were characterized by means of Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (1H NMR) spectroscopy which showing an agreement with the proposed structure. All the PUs are soluble in a variety of organic solvents, and could be cast into transparent, tough films with good mechanical properties. The effects of molecular structure on thermal stability of the polymers were studied by thermo-gravimetric analyzer. The electrochemical behaviors were investigated by cycle voltammetry (CV) method, and the result revealed that there were a pair of reversible oxidative redox couples at potentials of 0.33V and 1.15V vs Ag/AgCl in acetonitrile solution. The electrochromic properties were examined by spectroelectrochemical methods. All the PUs exhibited excellent reversibility of electrochromic characteristics by continuous cyclic scans between 0V and 1.6V, with a color changing from yellow to blue. [Copyright &y& Elsevier]

Bredereck oxazole synthesis was utilized to create a series of novel D-A polymers based on the triphenylamine (TPA) derivative, 4,4′-Diformyltriphenylamine (DPA), 4,4′-((4-bromophenyl)azanediyl)dibenzaldehyde (BPA), and oxamide/dithiooxamide. The obtained novel polymers exhibited impressive solution processabilities and excellent thermal stabilities. In the entire processes of electrochemical oxidation, these polymer films exhibited excellent electrochromic (EC) performances, high optical contrasts (49.6–52.8 %), high coloration efficiencies (362–451 cm2·C−1), and excellent cycling stabilities (18.6–33.9 % decay) with a cycle time of 20 s. By applying voltage, electrofluorochromic (EFC) performance can also be adjusted. Furthermore, these polymers showed fluorescence (PL) in solvents and solvatochromic effects in absorption. The outcome was indicative of the addition of oxazole[5,4- d ]oxazoles (OzOz) and thiazolo[5,4- d ]thiazoles (TzTz), whose highly conjugate rigid planar structures can significantly increase molecule stabilities and minimizing volume shrinking during charge transfer. In addition, due to introducing bromine atoms, the p-π conjugations enhanced the conjugation degrees of the molecules, which facilitated the electron transfers. Experimental results show that these improvement schemes will pave a way for obtaining multi-function optoelectronic devices with long-term cyclic stabilities. [Display omitted] • The electrochromic stability was optimized by introducing TzTz-type/OzOz-type group to the polymers. • Polymers were synthesized using fewer steps and cheap raw materials. • The introduction of fluorescent chromophore the fluorescence properties of the polymer and increased their potential purposes. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Six kinds of new soluble high coloration efficiency electrochromic polymers were synthetised. • The polymers showed good solubility and film-forming ability. • The films of the polymers showed high electrochromic coloration efficiency and electrochromic stability. Abstract Here, we synthesized four kinds of monomers of 3,6-dibromo-(N-phenyl)carbazole with different substituent group, DCB, DDC, DNC and DTC, respectively, and used 4-(3-bromo-9H-carbazol-9-yl)benzaldehyde to react with triphenylamine (TPA) unit and hydrazine hydrate unit, respectively, to obtain the other two monomers, BCB-TPA and BCB-HH. Six novel polymers coded as PDCB-DF, PDDC-DF, PDNC-DF, PDCB-DTC-DF, PBCB-TPA-DF and PBCB-HH-DF, were synthesized by Suzuki reactions of 2,2'-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis(1,3,2-dioxaborinane) with the six kinds of monomers and their electrochemical and spectroelectrochemical properties were investigated. The polymers showed good solubility and film-forming ability. Flexible or robust films of them could be readily obtained via solution-casting. These polymers showed the onset temperatures in the range of 300–470 °C when the 10% weight loss of polymers. The polymer films showed high coloration efficiency (CE) (196-376 cm2·C−1) and electrochromic stability. These properties illustrate that the polymers have great application prospect as electrochromic materials. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The polymer materials based on isoindigo, including electrochromic, memory device, explosive detection and photodetector. • The polymers show strong fluorescence with a fluorescence quantum efficiency (Ф PL) of up to 32.5%. • The polymers exhibit good thermal stability, high electrochromic coloration efficiency, high performance memory device and fast response to TNT and TNP. Abstract We report here that a series of novel donor-acceptor (D–A) conjugated polymers based on isoindigo were synthesized and characterized. As novel electrochromic materials, their optical and electrochemical properties have been investigated. Cyclic voltammograms (CV) of the polymer films exhibit two pairs of obvious redox peaks in the range of 0.76–1.80 V with strong color changes in the visible and near infrared (NIR) regions. The coloring and bleaching time are in the range of 3.5–4.9 s and 4.4–5.0 s, respectively. The amount of char yield at 800 °C in nitrogen for polymers was in the range of 56–64%. Especially, the polymers show strong fluorescence with a fluorescence quantum efficiency (Ф PL) of up to 32.5% which is reported firstly. In addition, memory properties, explosive detection and photoelectric properties for polymers are studied which indicating promising results. [ABSTRACT FROM AUTHOR]

Two series of novel aromatic polyamides (PAs) were synthesized via polymer condensation reaction based on N,N'-bis(4-aminophenyl)-N,N'-di-1-naphthalenyl-[1,1′-biphenhyl]-4,4′-diamine, N,N'-bis(4-aminophenyl)-N,N'-diphenyl-4,4′-biphenyl diamine and different binary acids compounds. The structures of the monomers and polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), hydrogen nuclear magnetic resonance ( 1 H NMR). The electrochromic properties of the PAs were investigated by using the ultra-visible-near infrared (UV–Vis–NIR) spectrophotometer and electrochemical workstation. The color of the polymer films changed from light yellowish to brown, then atroceruleous or brilliant blue with an increasing potential. Then we discussed the relationship of morphology on coloration efficiency. The electrochemical impedance spectroscopy (EIS) also has been used to characterize the internal resistances of PAs film electrodes. [ABSTRACT FROM AUTHOR]