Dithieno[2,3‐d:2′,3′‐d′]naphtho[2,1‐b:3,4‐b′]dithiophene based medium bandgap conjugated polymers for photovoltaic applications

Three novel medium band gap (MBG) conjugated polymers (CPs) (named as P1, P2, and P3, respectively) were developed by copolymerizing 2,7‐dibromo‐10,11‐di(2‐hexyldecyloxy)dithieno[2,3‐d:2′,3′‐d′]naphtho[2,1‐b:3,4‐b′]dithiophene (NDT‐Br) with three different units: 2,5‐bis(tributylstannyl)thiophene, 2,5‐bis(trimethylstannyl)thieno[3,2‐b]thiophene and trans?1,2‐bis(tributylstannyl)ethene, respectively. The thermal, optical, and electrochemical properties of the polymers were investigated. All of the polymers have good thermal stability and medium band gap (～ 1.9 eV). Prototype bulk heterojunction photovoltaic cells based on the blend P1/P2/P3 and [6, 6] phenyl‐C61 butyric acid methyl ester (PC₆₁BM) were assembled and the photovoltaic properties were assessed. Power conversion efficiencies (PCEs) of 1.61% ～ 2.43% have been obtained under 100 mW cm^?2 illumination (AM1.5). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43288.     

Synthesis,characterization, and photophysical properties of novel poly(p‐phenylene vinylene) derivatives with conjugated thiophene as side chains

Two novel poly(p‐phenylene vinylene) (PPV) derivatives with conjugated thiophene side chains, P1 and P2, were synthesized by Wittig‐Horner reaction. The resulting polymers were characterized by ¹H‐NMR, FTIR, GPC, DSC, TGA, UV–Vis absorption spectroscopy and cyclic voltammetry (CV). The polymers exhibited good thermal stability and film‐forming ability. The absorption spectra of P1 and P2 showed broader absorption band from 300 to 580 nm compared with poly[(p‐phenylene vinylene)‐alt‐(2‐methoxy‐5‐octyloxy‐p‐phenylene vinylene)] (P3) without conjugated thiophene side chains. Cyclic voltammograms displayed that the bandgap was reduced effectively by attaching conjugated thiophene side chains. This kind of polymer appears to be interesting candidates for solar‐cell applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Novel soluble carbazole‐based poly(aryl ethers): Preparation,properties, and application for dispersing multiwalled carbon nanotubes

Effectively dispersing of carbon nanotubes (CNTs) is the key to producing high performance CNTs/poly(aryl ethers) (PAEs) composite materials. Here, a series of novel soluble carbazole‐based PAEs with different alkyl side‐chains were synthesized corresponding polymers P1, P2, P3, and P4, and characterized clearly by ¹H NMR and IR. All the polymers exhibited good mechanical properties and thermostabilities (T_g ～ 128–212 °C, T_d5% ～ 450–499 °C) as PAEs. Due to containing lots of large π‐conjugated carbazole derivative units and possess suitable solubility, these non‐conjugated polymers can wrap and disperse MWNTs well (238–416 mg/L) in CHCl₃, and the similar work has been reported rarely. This excellent property makes these polymers become a promising and ideal type solubilizer for CNTs/PAEs composite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46250.     

Synthesis of two D‐π‐A polymers π‐bridged by different blocks and investigation of their photovoltaic property

The synthesis, characterization, photophysical and photovoltaic properties of two 5,6‐bis(octyloxy)benzo[c][1,2,5]thiadiazole‐containing wide‐band‐gap donor and acceptor D‐π‐A alternating conjugated polymers (HSD‐a and HSD‐b) have been reported. These two polymers absorb in the range of 300–700 nm with a band gap of about 1.88 and 1.97 eV. The HOMO energy levels were ?5.44 eV for HSD‐a and ?5.63 eV for HSD‐b. Polymer solar cells with HSD‐b :PC₇₁BM as the active layer demonstrated a power conversion efficiency (PCE) of 2.59% with a high V_oc of 0.93 V, a J_sc of 7.3 mA/cm², and a comparable fill factor (FF) of 0.38 under simulated solar illumination of AM 1.5G (100 mW/cm²) without annealing. In addition, HSD‐a :PC₇₁BM blend‐based solar cells exhibit a PCE of 2.15% with a comparable V_oc of 0.64 V, J_sc of 8.75 mA/cm^?2, and FF of 0.40. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41587.     

Synthesis,structures, and density functional theory computational study of thiophene‐containing and fluorodecorated imine‐linked polymers

A new series of extended–conjugated and thermally stable thiophene‐containing imine‐linked polymers were synthesized via a Schiff‐base condensation reaction between aryl aldehydes and 2,6‐diaminopyridine building blocks. The backbones of the polymers were functionalized with phenyl, fluorosubstituted phenyl, thienyl, and pyridyl aromatic rings. The successful synthesis was confirmed with spectrochemical characterization techniques, including IR, ¹H‐NMR, ¹³C‐NMR, and elemental analyses. The electronic properties of the polymers were investigated with ultraviolet–visible (UV–vis) absorption spectroscopy; the properties were collected experimentally and calculated with density functional theory (DFT) in the gas phase. The maximum absorption calculated from DFT was higher than the experimental values by about 60 nm; this was attributed to the absence of the solvent effect in the DFT case. The frontier molecular orbital ((HOMO) highest occupied molecular orbital and (LUMO) lowest unoccupied molecular orbital), optical band gap (E_g), and total energy (E_T) values of the optimized structures were calculated. Apparently, there was a significant relation between the number of thiophene rings and the resulting E_g and E_T values. As the number of thiophene rings in the polymer chain increased, E_g and E_T decreased, and the thermal stability of the polymers increased. E_g and the absorption band edges were determined experimentally from the UV–vis and transmittance spectra, respectively. Poly(terthienyl–azomethine–pyridine–azomethine), with the highest thiophene content, had the lowest experimental and calculated E_g values (2.10 and 2.63 eV, respectively). In contrast, upon fluorination, poly[(2,5‐dithienyl–1,4‐difluorobenzene)–azomethine–pyridine–azomethine] exhibited the highest E_g (2.81 eV) and absorption band edges (2.94 eV), whereas the thermal stability decreased to 250 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44331.     

Stille cross‐coupling applied to get higher molecular weight polymers: Synthesis,optoelectronic, Voc properties,and solar cell application

Conjugated polymers are highly desirable for the photovoltaic applications. We report the synthesis, characterization, optoelectronic properties, and solar cell application of two polymers, namely, poly[(9,9‐didodecylfluorene‐2,7‐diyl)‐alt‐(2,2′:5′,2″‐terthiophene‐5,5″‐diyl)] (P1) and poly[(1,4‐bis(dodecyloxy)benzene‐2,5‐diyl)‐alt‐(2,2′:5′,2″‐terthiophene‐5,5″‐diyl)] (P2). The polymers were synthesized via Stille cross‐coupling reaction, and were characterized by the gel permeation chromatography, nuclear magnetic resonance, Fourier transform infrared, UV–vis, thermogravimetric analysis, and cyclic voltammetry analyses. The two copolymers are processable due to their good solubility in organic solvents (tetrahydrofuran, CHCl₃, toluene, chlorobenzene, and o‐dichlorobenzene). The optical band gaps (UV–vis, film, and E_g^opt) of the P1 and P2 are 2.04 and 2.00 eV, respectively. The density functional theory output structures showed that S ^… O space interaction is likely responsible for the higher planarity of P2. The polymers showed low HOMO energy levels (P1: −5.33 eV, P2: −5.05 eV). The E_HOMO for P1 is close to the E_HOMO (−5.4 eV) of an ideal polymer, which is an important, rare, and main origin of the observed higher V_oc (801–808 mV). The onset decomposition temperatures (T_d) for the P1 and P2 are 418°C and 365°C, respectively. The polymer solar cell based on the P1: C₆₀ (1: 1) and P2: C₆₀ (1: 1) blend showed a power conversion efficiency (PCE) of 0.94 and 0.71%, respectively. The composite polymer : PC₆₀BM = 1 : 2 increased PCE of the P1 (1.65%) and P2 (1.09%) under AM 1.5 illumination (100 mW/cm²). The study provided important examples to design donor–donor (D–D) polymers for the photovoltaic applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42147.     

Ionic polymers with expanded π‐conjugation systems derived from through‐space interaction in piperazinium and homopiperazinium rings

Reactions of N‐(2,4‐dinitrophenyl)‐4‐arylpyridinium chlorides (aryl (Ar) = phenyl and 4‐biphenyl) with piperazine or homopiperazine caused opening of the pyridinium ring and yielded polymers that consisted of 5‐piperazinium‐3‐arylpenta‐2,4‐dienylideneammonium chloride (? N(CH₂CH₂)₂N⁺ (Cl^?)?CH? CH?C(Ar)? CH?CH? ) or 5‐homopiperazinium‐3‐arylpenta‐2,4‐dienylideneammonium chloride (? N(CH₂CH₂CH₂)(CH₂CH₂)N⁺ (Cl^?)?CH? CH?C(Ar)? CH?CH? ) units. ¹H NMR spectral analysis suggested that the π‐electrons of the penta‐2,4‐dienylideneammonium group of the polymers were delocalized. UV‐visible spectral measurements revealed that the π‐conjugation system expanded along the polymer chains because of the orbital interaction between electrons of the two nitrogen atoms of the piperazinium and homopiperazinium rings. However, the π‐conjugation length depended on the distance between the two nitrogen atoms; that is, the polymers containing the piperazinium ring had a longer π‐conjugation length than those containing the homopiperazinium ring. Conversion of the piperazinium and homopiperazinium rings from the boat to the chair form led to a decrease in the π‐conjugation length. The surface of pellets that were molded from the polymers exhibited metallic luster, and these polymers underwent electrochemical oxidation in solution. Copyright © 2010 Society of Chemical Industry     

Photocatalytic Performance of Nitrogen‐Doped and Cu2+ and Ag+ Co‐Doped Sodium Trititanate

Nano‐sized (i) N‐doped sodium trititanate and (ii) N and Cu²⁺ (Ag⁺) co‐doped sodium trititanates CuTi₃NO_6?x (Ag₂Ti₃NO_6?x) were prepared by a solid‐state and ion‐exchange methods, respectively. The materials were characterized by EDS, PXRD, XPS, FESEM, TEM, UV–visible DRS, and Raman spectroscopy. All the materials were crystallized in monoclinic lattice with P21/m space group. The bandgap energy of all the samples was deduced from their UV–visible DRS profiles. Visible‐light‐induced photocatalytic oxidation of the methylene blue (MB) and methyl orange (MO), cyclohexene and phenol, was examined. The Ag⁺ co‐doped trititanate exhibited the highest photocatalytic activity among the materials investigated.     

Well‐functioned photovoltaics based on nanofibers composed of PBDT‐TIPS‐DTNT‐DT and graphenic precursors thermally modified by polythiophene,polyaniline and polypyrrole

Reduced graphene oxide nanosheets modified by conductive polymers including polythiophene (GPTh), polyaniline (GPANI) and polypyrrole (GPPy) were prepared using the graphene oxide as both substrate and chemical oxidant. UV–visible and Raman analyses confirmed that the graphene oxide simultaneously produced the reduced graphene oxide and polymerized the conjugated polymers. The prepared nanostructures were subsequently electrospun in mixing with poly(3‐hexylthiophene) (P3HT)/phenyl‐C71‐butyric acid methyl ester (PC₇₁BM) and poly[bis(triisopropylsilylethynyl)benzodithiophene‐bis(decyltetradecylthien)naphthobisthiadiazole] (PBDT‐TIPS‐DTNT‐DT)/PC₇₁BM components and embedded in the active layers of photovoltaic devices to improve the charge mobility and efficiency. The GPTh/PBDT‐TIPS‐DTNT‐DT/PC₇₁BM devices demonstrated better photovoltaic features (J_sc = 11.72 mA cm^?2, FF = 61%, V_oc = 0.68 V, PCE = 4.86%, μ_h = 8.7 × 10^?3 cm² V^–1 s^?1 and μ_e = 1.3 × 10^?2 cm² V^–1 s^?1) than the GPPy/PBDT‐TIPS‐DTNT‐DT/PC₇₁BM (J_sc = 10.30 mA cm^?2, FF = 60%, V_oc = 0.66 V, PCE = 4.08%, μ_h = 1.4 × 10^?3 cm² V^–1 s^?1 and μ_e = 8.9 × 10^?3 cm² V^–1 s^?1) and GPANI/PBDT‐TIPS‐DTNT‐DT/PC₇₁BM (J_sc = 10.48 mA cm^?2, FF = 59%, V_oc = 0.65 V, PCE = 4.02%, μ_h = 8.6 × 10^?4 cm² V^–1 s^?1 and μ_e = 7.8 × 10^?3 cm² V^–1 s^?1) systems, assigned to the greater compatibility of PTh in the nano‐hybrids and the thiophenic conjugated polymers in the bulk of the nanofibers and active thin films. Furthermore, the PBDT‐TIPS‐DTNT‐DT polymer chains (3.35%–5.04%) acted better than the P3HT chains (2.01%–3.76%) because of more complicated conductive structures. © 2019 Society of Chemical Industry     

Synthesis,characterization, and properties of new 3‐hexyl‐2,5‐diphenylthiophene: Phenylene vinylenes copolymers as colorimetric sensor for iodide anion

Four new conjugated copolymers P1 ‐ P4 have been prepared by the Horner‐Emmons and Knoevenagel polymerization reactions. P1 ‐ P4 were characterized by NMR, FTIR, cyclic voltammetry (CV), diffuse reflectance UV–vis spectroscopy (DR UV–vis), and thermal gravimetric analysis (TGA). The optical band gaps of these polymers, calculated from the onset absorption edge, were found between 2.15 and 2.34 eV. The band gaps calculated by CV were ranged between 1.94 and 2.57 eV. The presence of nitrile moiety on the phenylene vinylene unit is believed to influence the optical properties of these polymers, i.e., P3 and P4 have shown lower band gaps than P1 and P2 . All polymers possess good iodide anion sensing property over a wide range of other anions (F^?, Cl^?, Br^?, , CN^?), indicating their promise in fabricating selective iodide sensors. The initial colorless solution of polymers in THF changed to deep yellow upon the addition of aqueous solution of iodide salts along with significant changes in the UV–vis spectra of the polymers. The limit of detection (LOD) for P1‐P4 were found between 0.43 and 2.54 mM . These polymers constitute long alkoxy and alkyl side chains, bearing excellent solubility in most common organic solvents which warrants their suitability for photovoltaic devices application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44948.     

Optical limiting materials: Synthesis,electrochemical and optical studies of new thiophene based conjugated polymers carrying 1,3,4‐oxadiazole units

In this communication we report synthesis of three new donor‐acceptor (D–A) type conjugated polymers carrying 1,3,4‐oxadiazole moiety and thiophene unit with different side groups at its 3,4 positions (4‐methoxybenzyl:P1, 3‐methylbenzyl:P2 and 4‐nitrobenzyl:P3) through polycondensation route using a series of newly synthesized monomers. The structures of new monomers and polymers were confirmed by NMR, FTIR spectroscopic methods followed by elemental analysis. Further, molecular weight and thermal stability were determined using gel permeation chromatography and thermogravimetric analysis. The linear optical and electrochemical properties of polymers were investigated by UV–vis absorption, fluorescence spectroscopic, and cyclic voltammetric studies. The polymers P1–P3 were found to be thermally stable and their electrochemical band gaps were determined to be 1.98, 2.14, and 2.18 eV respectively. Further their nonlinear optical properties were investigated by Z‐scan method using 532 nm, 7 ns laser pulses. The results reveal that they possess good optical limiting behavior due to effective three‐photon absorption (3PA) with absorption coefficient 2.5 × 10^?24 m^?3W², 1.6 × 10^?24 m^?3W², and 1.0 × 10^?24 m^?3W². POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

New thiophene‐based donor–acceptor conjugated polymers carrying fluorene or cyanovinylene units: Synthesis,characterization, and electroluminescent properties

Two new thiophene‐based donor–acceptor (D–A) conjugated polymers, PDTOFV and PDTOCN, are synthesized and characterized. The polymers are readily soluble in common organic solvents and exhibit good thermal stability with onset decomposition temperature (T_d) in the range 310?330°C. Cyclic voltammetry studies revealed that polymers possess low‐lying highest occupied molecular orbital (HOMO) energy levels (?5.94 eV for PDTOFV and ?5.86 eV for PDTOCN) and low‐lying lowest unoccupied molecular orbital (LUMO) energy levels (?3.35 eV for PDTOFV and ?3.55 eV for PDTOCN). The optical band gap is calculated from onset absorption edge of the polymer film. The polymers exhibit green fluorescence with fluorescence quantum yields (?_fl) of 38% and 42%, respectively, for PDTOFV and PDTOCN. Polymer light‐emitting diodes (PLEDs) are fabricated using these polymers with a device configuration of ITO/PEDOT:PSS/polymer/Al. The device based on PDTOFV emitted green light with Commission Internationale de I'Eclairage (CIE) coordinate values of (0.25, 0.39). Whereas, the device based on PDTOCN showed white light emission with CIE coordinate values of (0.32, 0.35), which is very close to the values (0.33, 0.33) of standard white light emission. The threshold voltages of the PLEDs are determined by current density‐voltage characteristics and are found to be 7.3 and 3.9 V for PDTOFV and PDTOCN, respectively. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Synthesis and characterization of novel polyphenol species derived from bis(4‐aminophenyl)ether: Substituent effects on thermal behavior,electrical conductivity,solubility, and optical band gap

In this study, four different Schiff bases namely 4,4′‐oxybis[N‐(2‐hydroxybenzilidene)aniline] (2‐HBA), 4,4′‐oxybis[N‐(4‐hydroxybenzilidene)aniline] (4‐HBA), 4,4′‐oxybis[N‐(3,4‐dihydroxybenzilidene)aniline] (3,4‐HBA), and 4,4′‐oxybis[N‐(4‐hydroxy‐3‐methoxybenzilidene)aniline] (HMBA) were synthesized. These Schiff bases were converted to their polymers that have generate names of poly‐4,4′‐oxybis[N‐(2‐hydroxybenzilidene)aniline] (P‐2‐HBA), poly‐4,4′‐oxybis[N‐(4‐hydroxybenzilidene)aniline] (P‐4‐HBA), poly‐4,4′‐oxybis[N‐(3,4‐dihydroxybenzilidene)aniline] (P‐3,4‐HBA), and poly‐4,4′‐oxybis[N‐(4‐hydroxy‐3‐methoxybenzilidene)aniline] (PHMBA) via oxidative polycondensation reaction by using NaOCl as the oxidant. Four different metal complexes were also synthesized from 2‐HBA and P‐2‐HBA. The structures of the compounds were confirmed by FTIR, UV‐vis, ¹H and ¹³C NMR analyses. According to ¹H NMR spectra, the polymerization of the 2‐HBA and 4‐HBA largely maintained with C? O? C coupling, whereas the polymerization of the 3,4‐HBA and HMBA largely maintained with C? C coupling. The characterization was made by TG‐DTA, size exclusion chromatography and solubility tests. Also, electrical conductivity of the polymers and the metal complex compounds were measured, showing that the synthesized polymers are semiconductors and their conductivities can be increased highly via doping with iodine ions (except PHMBA). According to UV–vis measurements, the optical band gaps (E_g) were found to be 3.15, 2.06, 3.23, 3.02, 2.61, 2.47, 2.64, 2.42, 2.83, 2.77, 2.78, and 2.78 for 2‐HBA, P‐2‐HBA, 4‐HBA, P‐4‐HBA, 3,4‐HBA, P‐3,4‐HBA, HMBA, PHMBA, 2‐HBA‐Cu, 2‐HBA‐Co, P‐2‐HBA‐Cu, and P‐2‐HBA‐Co, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and properties of conducting polypyrrole,polyalkylanilines, and composites of polypyrrole and poly(2‐ethylaniline)

Conducting polymers of alkylanilines, pyrrole, and their conducting composites were synthesized by oxidation polymerization. The oxidants used were KIO₃ and FeCl₃ for the polyalkylanilines and polypyrrole (PPy), respectively. Among the polyalkylanilines synthesized with KIO₃ salt, the highest conductivity was obtained with poly(2‐ethylaniline) (P2EAn) with a value of 4.10 × 10^?5 S/cm. The highest yield was obtained with poly(N‐methylaniline) with a value of 87%. We prepared the conducting composites (PPy/P2EAn and P2EAn/PPy) by changing synthesis order of P2EAn and PPy. The electrically conducting polymers were characterized by IR spectroscopy, ultraviolet–visible spectroscopy, thermogravimetric analysis, and X‐ray diffraction spectroscopy. From the results, we determined that the properties of the composites were dependent on the synthesis order of the polymers. The thermal degradation temperature of PPy was observed to be higher than that of the other polymers and composites. We determined from X‐ray results that the structures of the homopolymers and composites had amorphous regions (88–95%) and crystal regions (5–12%). From the Gouy balance magnetic measurements, we found that the polymers and composites were bipolaron conducting mechanisms. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 241–249, 2006     

Synthesis and characterizations of poly(4‐alkylthiazole vinylene)

Two poly(thiazole vinylene) derivatives, poly(4‐hexylthiazole vinylene) (P4HTzV) and poly(4‐nonylthiazole vinylene) (P4NTzV), were synthesized by Pd‐catalyzed Stille coupling method. The polymers are soluble in common organic solvents such as o‐dichlorobenzene and chloroform, and possess good thermal stability. P4HTzV and P4NTzV films exhibit broad absorption bands at 400–720 nm with an optical bandgap of 1.77 eV and 1.74 eV, respectively. The HOMO (the highest occupied molecular orbital) energy levels of P4HTzV and P4NTzV are ?5.11 and ?5.12 eV, respectively, measured by cyclic voltammetry. Preliminary results of the polymer solar cells based on P4HTzV : PC₆₁BM ([6,6]‐phenyl‐C‐61‐butyric acid methyl ester) (1 : 1, w/w) show a power conversion efficiency of 0.21% with an open‐circuit voltage of 0.55 V and a short circuit current density of 1.11 mA cm^?2, under the illumination of AM1.5G, 100 mW cm^?2. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and spectroelectrochemistry of dithieno(3,2‐b:2′,3′‐d)pyrrole derivatives

New π‐conjugated polymers containing dithieno(3,2‐b:2′,3′‐d)pyrrole (DTP) were successfully synthesized via electropolymerization. The effect of structural differences on the electrochemical and optoelectronic properties of the 4‐[4H‐dithieno(3,2‐b:2′,3′‐d)pyrrol‐4‐yl]aniline (DTP–aryl–NH₂), 10‐[4H‐dithiyeno(3,2‐b:2′,3′‐d)pirol‐4‐il]dekan‐1‐amine (DTP–alkyl–NH₂), and 1,10‐bis[4H‐dithieno(3,2‐b:2′,3′‐d)pyrrol‐4‐yl] decane (DTP–alkyl–DTP) were investigated. The corresponding polymers were characterized by cyclic voltammetry, NMR (¹H‐NMR and ¹³C‐NMR), and ultraviolet–visible spectroscopy. Changes in the electronic nature of the functional groups led to variations in the electrochemical properties of the π‐conjugated systems. The electroactive polymer films revealed redox couples and exhibited electrochromic behavior. The replacement of the DTP–alkyl–DTP unit with DTP–aryl–NH₂ and DTP–alkyl–NH₂ resulted in a lower oxidation potential. Both the poly(10‐(4H‐Dithiyeno[3,2‐b:2′,3′‐d]pirol‐4‐il)dekan‐1‐amin) (poly(DTP–alkyl–NH₂)) and poly(1,10‐bis(4H‐dithieno[3,2‐b:2′,3′‐d]pyrrol‐4‐yl) decane) (poly(DTP–alkyl–DTP)) films showed multicolor electrochromism and also fast switching times (<1 s) in the visible and near infrared regions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40701.     

Synthesis,characterization, thermal stability,conductivity, and band gap of a new aromatic polyether containing an azomethine as a side

In this study, the oxidative polycondensation reaction conditions of 4‐[(4‐methylphenyl)iminomethyl]phenol (4‐MPIMP) were studied by using oxidants such as air O₂, H₂O₂, and NaOCl in an aqueous alkaline medium between 50 and 90°C. The structures of the synthesized monomer and polymer were confirmed by FTIR, UV–vis, ¹H–¹³C‐NMR, and elemental analysis. The characterization was made by TGA‐DTA, size exclusion chromatography (SEC), and solubility tests. At the optimum reaction conditions, the yield of poly‐4‐[(4‐methylphenyl)iminomethyl]phenol (P‐4‐MPIMP) was found to be 28% for air O₂ oxidant, 42% for H₂O₂ oxidant, and 62% for NaOCl oxidant. According to the SEC analysis, the number–average molecular weight (M_n), weight–average molecular weight (M_w), and polydispersity index values of P‐4‐MPIMP were found to be 4400 g mol^?1, 5100 g mol^?1, and 1.159, using H₂O₂, and 4650 g mol^?1, 5200 g mol^?1, and 1.118, using air O₂, and 5100 g mol^?1, 5900 g mol^?1, and 1.157, using NaOCl, respectively. According to TG analysis, the weight losses of 4‐MPIMP and P‐4‐MPIMP were found to be 85.37% and 72.19% at 1000°C, respectively. P‐4‐MPIMP showed higher stability against thermal decomposition. Also, electrical conductivity of the P‐4‐MPIMP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels and electrochemical energy gaps (E) of 4‐MPIMP and P‐4‐MPIMP were found to be ?5.76, ?5.19; ?3.00, ?3.24; 2.76 and 1.95 eV, respectively. According to UV–vis measurements, optical band gaps (E_g) of 4‐MPIMP and P‐4‐MPIMP were found to be 3.34 and 2.82 eV, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and chemical properties of dielectric polyphenylenes with nitro group

Polyphenylenes consisting of nitrophenylene and didodecyloxy‐p‐phenylene units have been synthesized by Pd‐catalyzed organometallic polycondensation. The polymers showed good solubility and had number–average molecular weights (M_n) of 13,000–37,000. Their spin‐coated films showed fairly high dielectric constants (ε) of 3.75–6.36. The polymers were electrochemically active with electrochemical reduction peaks in the range of ?1.72 to ?1.99 V versus Ag⁺/Ag in an acetonitrile solution of [NEt₄]BF₄ (0.10M). The polymer composed of 2,3′‐dinitrobiphenyl and didodecyloxy‐p‐phenylene units showed thermotropic liquid crystalline phase at about 240°C. Cast films of the polymer had a birefringent phase at room temperature, suggesting self‐assembly of the polymer in the solid. XRD studies revealed that the polymers assumed an ordered structure assisted by aggregation of the long alkoxy side chains in the solid. The polymer main chain in the cast film is considered to be aligned parallel with respect to the surface of substrates. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Pyrrole‐based narrow‐band‐gap copolymers for red light‐emitting diodes and bulk heterojunction photovoltaic cells

A series of narrow‐band‐gap conjugated copolymers (PFO‐DPT) derived from pyrrole, benzothiadiazole, and 9,9‐dioctylfluorene (DOF) is prepared by the palladium‐catalyzed Suzuki coupling reaction with the molar feed ratio of 4,7‐bis(N‐methylpyrrol‐2‐yl)‐2,1,3‐benzothiadiazole (DPT) around 1, 5, 15, 30, and 50%. The obtained polymers are readily soluble in common organic solvents. The solutions and the thin solid films of the copolymers absorb light from 300 nm to 600 nm with two absorbance peaks at around 380 nm and 505 nm. The PL emission consists mainly of DPT unit emission at around 624–686 nm depending on the DPT content in solid film. The EL emission peaks are red‐shifted from 630 nm for PFO‐DPT1 to 660 nm for PFO‐DPT50. Bulk heterojunction photovoltaic cells fabricated from composite films of copolymer and [6,6]‐phenyl C₆₁ butyric acid methyl ester (PCBM) as electron donor and electron acceptor, respectively, in device configuration: ITO/PEDOT : PSS/PFO‐DPT : PCBM/Ba/Al shows power conversion efficiencies 0.15% with open‐circuit voltage (V_oc) of 0.60 V and short‐circuit current density (J_sc) of 0.73 mA/cm² under AM1.5 solar simulator (100 mW/cm²). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Amphiphilic copolymer with pendant pyrenebutyryl hydrazide group: Synthesis,characterization, and recognition for carbonate anion

Novel hydrophobic monomer N‐(1‐pyrenebutyryl)–N′‐methacryloyl hydrazide (PyMAHy) was synthesized and copolymerized with N‐vinylpyrrolidone (NVP) to get a series of amphiphilic copolymers. FTIR, ¹H NMR, TEM, gel permeation chromatography–multi‐angle laser light scattering, UV–vis spectroscopy, and fluorescence spectroscopy were used to characterize these polymers. Results of fluorescence measurements show that these copolymers have good recognition ability to CO₃^2? anion and the fluorescence emission intensity was quenched linearly upon the addition of CO₃^2? anion. The recognition for CO₃^2? anion was also proved by the results of TEM for the significantly difference in the morphology of copolymer before and after adding CO₃^2? anion into copolymer Tris–HCl buffer solution. Results suggest the potential of these amphiphilic copolymers as fluorogenic chemosensor materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2371–2376, 2006