Carbazole Polymers Research Articles

Copolymerization of pyrrole and carbazole onto polyester textile.

The purpose of this study was the polymerization of carbazole (Cz), pyrrole (Py) and copolymerization of them onto polyester (PES) textile with chemical oxidative method by using FeCl3. First, in order to determine the optimum conditions, the effect of polymerization steps, the immersion order of the PES to the oxidant and monomer solutions, time, monomer, oxidant, and surfactant concentrations and types on the conductivities of PES/PCz composite were investigated and at this conditions, conductive composite, PES/P[Py-co-Cz] was obtained. The highest conductivities were obtained as 12.4 mS/cm and 9.0 mS/cm for PES/PCz and PES/P[Py-co-Cz], respectively. Further characterization of PES/P[Py-co-Cz] was performed by conductivity, FTIR, scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA) measurements, and results were compared with PES/PCz and also PES/PPy. The presence of Py and Cz in the same polymer chain created synergy and improved the conductivity and mechanical properties of the composite.

9-Vinyl-9H-carbazole-3,6-dicarbonitrile

Carbazole polymers attract significant attention as promising luminophores, organic electronic and photovoltaic materials, photo/electrocatalysts, energy storage materials, redox mediators and catalysts. However, the oxidation potential of the commercially available poly(vinylcarbazole) is insufficient for some applications such as high-voltage Li-Ion batteries. We have proposed a monomer for the novel polycarbazole with an increased oxidation potential, which will be compatible with high-voltage cathode materials for Li-Ion. In addition, the proposed polymer is an interesting substrate for the further carbonization to obtain N-doped carbons with a high electrocatalytic activity level.

Ultrasound and Pressure Assisted Solid‐State Polymerization of Carbazole

AbstractThis study was carried out with the aim of obtaining polycarbazole (PCz) with solid‐state polymerization by using ultrasound and pressure assisted methods. For ultrasound‐assisted method (U), first, the optimum carbazole (Cz) and cerium ammonium nitrate (CAN) amounts, polymerization time, ultrasound application conditions were determined and then the polymers that are called “PCz‐U#” were characterized by using scanning electron microscope (SEM), fourier transform infrared spectroscopy (FT‐IR), thermal gravimetric analysis (TGA), transmission electron microscobe (TEM), X‐ray diffraction (XRD) and four‐point prop conductivity measurements. The effect of the applied pressing time during preparation of pellet on the conductivity of PCz‐U was also investigated. Pressure‐assisted polymerization (P) was carried out at these optimum conditions and the resulting polymer was called “PCz‐P#”.In order to understand the advantage of the ultrasound and pressure assisted methods, conventional polymerization in a solution was also performed at the optimum concentrations of Cz and CAN and the properties of PCz's obtained from three different methods were compared. The conductivities of PCz's obtained in a very short time such as one minute with the ultrasound and pressure assisted methods are at the same level as the conductivity of the polymer (∼10−4 S/cm) obtained by the solution method in 20 minutes using 16 and 35.6 times higher amounds of Cz and CAN, respectively. With this study, two new methods for PCz synthesis have been proposed, which are suitable for VOC limitation as no solvent is used in and environmentally friendly because less chemicals are used.

Preparation of Polycarbazole Nanofibers Using an Electric Field and the Investigation of Its Electrical Conductivity

In conventional chemical and electrochemical oxidation methods, it is very difficult to control the active centers, and the average prepared polymers are short and wide. The use of an electric field creates the most stable intermediate form of active centers, as well as permitting a longer half-life. Therefore, this increases the physical resistance and electrical conductivity of the polymer. In this paper, polycarbazole nanofibers were prepared using an electric field, reporting on its influences on the polymerization of carbazole. Therefore, its electrical conductivity and some physical properties were investigated. We observed the nanofibers’ shape, increasing electrical conductivity, thermal resistance and a higher molecular weight with the synthesized polycarbazole under an electric field compared to the polymer synthesized in the same conditions in the absence of an electric field. First, we chemically synthesized polycarbazole at different times. Additionally, to find the optimizing conditions, we changed certain parameters, such as the ratio of the obtained molar of initiator to monomer, the oxidant, initiator and solvent, separately, and compared the obtained results. Then, we repeated this reaction in the best conditions and under different electric fields in constant time, allowing us to characterize the shape, mass and conductivity. Next, the polymerization was carried out at the best electric field in different times. Finally, the best time and amount of electric field for polymerization were determined. The electrical conductivity of polycarbazoles was studied with the four-probe method. The conductivity of the films oxidized using FeCl3 (dry) and protonated with p-toluenesulfonic acid (PTSA) at 3 h was higher than 8.9 × 10−4 S/cm under a 12 KV/m electric field. Additionally, the results showed an enhanced thermal resistance to ageing.

Suitability of ZnO Nanocomposite of Copolymer (PPy-PNVK-ZnO) (PPy = Polypyrrole; PNVK = Poly 9-vinyl carbazole) for the Detection of 6-Thioguanine: A DFT Analysis

Conducting polymers have extensively been exploited for the specific drug detection, through diverse drug responses. 6-Thioguanine (6-TG) is commonly used in the treatment of cancer and its level monitoring in the human body is essential to avoid the side effects due to its physiological metabolites. Computational synthesis of a novel sensor material, i.e. ZnO nanocomposite of copolymer (PPy-PNVK-ZnO) using polypyrrole (PPy-ZnO) and poly 9-vinyl carbazole (PNVK-ZnO) polymers, has been performed and investigated its sensing ability for 6-TG drug, using the density functional theory (DFT) based ab initio approach. Generalized gradient approximation (GGA), parameterized with Perdew, Burke and Ernzerhof (PBE) type parameterization furnishes novel resources on the studied molecular model. The molecular interactions have been analyzed in terms of the HOMO-LUMO gap, density of states (DOS), adsorption energy (Eads), recovery time (τ), Mulliken population, electron density plot and quantum molecular descriptors. The calculated negative adsorption energy confirms the stability of these polymers and observes the type of interaction with 6-TG, as physical adsorption, that also confirms the reusability of the prepared sensor and its low operational temperature. It has also been observed that ZnO nanocomposite of copolymer has favourable stability in comparison to its host counterparts, whereas the host PNVK has a better recovery time and PPy has a relatively better range of detection and highly reactive.

Study on Spectro-Electrochemical Behaviour of Thin-Layer Polymer of 3-(9H-Carbazol-9-yl)propanenitrile

A film of electrically active poly(3-(9H-carbazol-9-yl)propanenitrile) was prepared on platinum (Pt) electrode surface by oxidative electro-polymerization of 3-(9H-carbazol-9-yl)propanenitrile monomer. The polymerization reaction was performed in a reaction medium containing monomer, and 0.1 M tetrabutylammonium tetrafluoroborate (TBABF4 ) mixture in acetonitrile (ACN) using repeated cycling at a scanning rate of 250 mV. Electrochemical polymerization of carbazole (Cz) and 3-(9H-carbazol-9-yl)propanenitrile (25 mM) were studied with cyclic voltammetry on both Pt and ITO electrodes. The structure of the poly(3-(9H-carbazol-9-yl)propanenitrile) was elucidated by nuclear magnetic resonance (1H and 13C NMR) and Fourier transform infrared (FTIR) spectroscopy. The weight average molecular weight (Mw) of the electrochemically synthesized poly(3-(9H-carbazol-9-yl)propanenitrile) was determined using gel permeation chromatography (GPC), where it was found that the Mw of the polymer is equal to 37900 g/mol. The polymer was characterized using dry conductivity measurement, scanning electron microscopy (SEM) and UV-Vis spectroscopy, while the spectro-electrochemical studies indicated that poly(3-(9H-carbazol-9-yl)propanenitrile) films revealed a green color in the oxidized state and a high transmittance in the neutral state. Moreover the poly(3-(9H-carbazol-9-yl)propanenitrile) film is soluble in common organic solvents, like DMSO, THF, NMP and DMAC. The conductivity of poly(3-(9H-carbazol-9-yl)propanenitrile) was found to be 1.62x10-4 S/cm.

Electrochemical preparation and physicochemical study of polymers obtained from carbazole and N-((methoxycarbonyl)methyl)carbazole

The polymerization of carbazole (Cz) and N-((methoxycarbonyl)methyl)carbazole (CzE) was carried out by electrochemical oxidation in acetonitrile solution. Different feed ratios of monomers were used to deposit polymer thin films with different compositions and study the influence of the ratio of monomers on the electrochemical, morphological, mechanical and adhesive properties of the polymer films. The electrochemical oxidation led to the deposition of a polymer film whatever the feed ratio but the thickness of the film increased with the portion of unmodified carbazole. On the contrary, the composition of the monomer mixture had a low influence on the AFM adhesion forces between the AFM tip and the polymer film. Depending on the feed monomer ratio, the morphology was either globular or columnar (when the portion of CzE was comprised between 10% and 70%). The stiffness of the polymer films was also found to be strongly dependent on the feed ratio since it varied from 2 to 115 GPa depending on the monomer ratio. The polymer films prepared from the ratios 90:10 and 70:30 in Cz:CzE monomer solutions were found to be the most interesting ones since they led to thick and conducting polymer films with a good adhesion and a low stiffness. Moreover, these coatings were uniform and exhibited an original columnar structure.

Organic Electropolymerized Multilayers for Light-Emitting Diodes and Displays.

In electrochemistry, the carbazole is generally coupled to dimer but not to polymer. This work has reported that organic electropolymerization (OEP) of 4,4',4″-tri(N-carbazolyl)triphenylamine (TCTA) would form a high cross-linked carbazole polymer by its high activity/reversibility and a synchronous viscosity control. It has significantly improved the OEP film quality of both hole-transporting and electroluminescent layers in organic light-emitting diodes. As a result, the conductivity and power efficiency of the organic light-emitting diodes with TCTA are eight and four times of that without TCTA. A prototype display device with a 1.7 in. monochrome passive matrix of 58 ppi under the driving chip is successfully fabricated with accurate pixel size and uniform electroluminescence, which shows a great potential of OEP in the electroluminescent application.

Synthesis, characterization, aggregation-induced emission and nanoaggregates of the copolymers containing different ratios of carbazoles and tetraphenylethylenes

In this work, polymers comprising of the different ratios of N-decyl or N-triethylene glycol substituted 2,7-carbazoles and tetraphenylethenes were designed and synthesized by palladium-catalyzed Suzuki Miyaura cross-coupling reaction of their corresponding comonomers. The copolymers containing carbazoles and tetraphenylethenes showed aggregation induced emission characteristics in both solid state and aggregate state when the composition of the tetraphenylethenes reached to 50%. N-triethylene glycol substituted carbazole polymers revealed lower bandgap and higher HOMO level compared to that of the N-decyl substituted carbazole polymers. The higher composition of the tetraphenylethenes, the deeper HOMO level and the larger bandgap of the polymers. Polymers with 1:1 molar ratio of the carbazoles and the tetraphenylethenes exhibited sphere-like nanoparticles with an average diameter of around 30 nm. The polymers containing carbazole and TPE units in 3:1 or 1:3 molar ratio self-assembled to form nanoaggregates with a size of around 100 nm.

Study on Carbazole-like Polymer Solar Cell Materials

<p>With the development of modern industry, the global energy crisis and air pollution problems become increasingly prominent. Solar energy has emerged as an ideal renewable energy by many countries’ attention. Solar cells are the most promising use of solar energy in the kind of concern. Compared with inorganic solar cells, polymer solar cells performance is more excellent and carbazole polymer materials with rigid fused ring structure, intramolecular electron transfer, good transport and easy to introduce a variety of multi-functional groups into the carbazole. The advantages of the ring in the field of solar cell materials show a wide range of potential applications. This paper describes the principles of polymer solar cells and several common donor materials. The precursors of carbazole polymers were designed and synthesized, and their structures were characterized. </p>

Synthesis and luminescence properties of long-chain (2,7-carbazolyl)-adamantane copolymers

Several long-chain (2,7-carbazolyl) adamantane copolymers, with molecular weight ranging from 4500 to 6000, were synthesized by palladium-catalyzed Suzuki reaction using 1,5-bis (4-bromophenyl) adamantane and N-(2-ethylhexyl)-2,7-carbazole as building molecules. The copolymers were characterized by infrared, ultraviolet, nuclear magnetic resonance (NMR), fluorescence spectroscopies, and thermal analysis. It was found that the introduction of adamantyl group into the backbone of conjugated carbazole polymer significantly improves the thermal stability and spectral stability of the copolymer. These copolymers giving high color purity showed excellent comprehensive performance: the thermal decomposition temperature is up to 409 ~ 432 °C, glass-transition temperature is about 83 ~ 162 °C, fluorescence quantum efficiency is as high as 0.76 ~ 0.85. Hence, the synthesized copolymers have great potential for being used as new blue-light-emitting materials.

Organic Functionalization and Properties of ZnO Nanosheets with Polymer Containing N-Vinyl Carbazole

To make full use of the visible light more effectively, many studies are focuses on ZnO baesd nanocomposites. To modify the surface of ZnO with functional polymer is a very simple and effective approach. PVK (N-vinyl carbazole polymer) is one of typical organic functional materials, which is generally used as charge transfer materials for the applications of several organic electronic devices. Surface modification of ZnO nanosheets with polymer containing –COOH and N-vinyl carbazole group was performed with self-assembly process for improving the adsorption to visible light and properties of charge transfer in nanoscale. A series of characterizations were carried out by SEM (scanning electron microscopy), Fourier-Transform Infrared (FTIR) spectra, UV-Vis (Ultra-violet visible spectroscopy), et al. The adsorption of the nanocomposite was extended to the region of visible light. The photoconductivity response to weak visible light was studied based on interdigital electrodes of Au on flexible PET (polyethylene terephthalate) film substrate with casting method. The photocurrent of ZnO nanosheets modified with the polymer containing N-vinyl carbazole to weak visible light was changed greatly. The organic-inorganic nanocomposite showed good activities to visible light, with which it can be easily produced photo-induced charges, avoiding the recombination of charges produced by visible light. Photocatalytic efficiency was examined by selecting typical organic pollutants and some good results were obtained, showing much prospect in the fields of photocatalysts, nanoreactors, self-cleaning films, coatings, and organic pollutants treatment of environmental.

Dual substitution at 4,9-positions of carbazole in donor-π-acceptor copolymer enhances performance of bulk-heterojunction organic solar cells

Several carbazole-2,7-diyl units with alkoxy substituents at the 4-position in addition to branched (1-alkyl)alkyl substituents at the 9-position were developed and combined with difluorinated dithienylbenzothiadiazole by using a Suzuki coupling reaction to synthesize donor–π–acceptor-type copolymers. X-ray diffraction analyses of these copolymers revealed that the 4,9-disubstituted carbazole unit contributed to form a balanced interdigitated structure, which resulted in smaller π-stacking distances (4.0–3.5 Å) of the polymer backbone, a narrower bandgap (2.0–1.8 eV), and higher hole mobilities (4.2 × 10−4 to 2.9 × 10−3 cm2 V−1 s−1) than those of the carbazole copolymer without the 4-substituent (PCDT2FBT). A bulk heterojunction organic photovoltaic device with a configuration of ITO/PEDOT:PSS/polymer:PC70BM/LiF/Al exhibited a power conversion efficiency of 5.46%, a short-circuit current density of 12.4 mA cm−2, a fill factor of 0.58, and an open-circuit voltage of 0.76 V. The photovoltaic performance was much higher than that of PCDT2FBT. These results demonstrate that incorporation of the side chains into the 4,9-positions of carbazole is a novel approach to obtain self-organizing carbazole polymers, enabling improvement in light absorption, hole mobility, and photovoltaic performance.

Four Simple Structure Carbazole‐Based Conjugated Microporous Polymers with Different Soft Connected Chains

Four carbazole–spacer–carbazole polymers PCz–Cn–Cz (n = 3–6) with the similar topological model structures are designed and prepared by FeCl3 oxidative coupling polymerization. The Brunauer–Emmett–Teller (BET) specific surface areas of polymers are 862, 870, 768 and 785 m2 g−1, respectively. Interestingly, there are no obvious differences in the domain pore width (centered at 0.5 nm) and the pore size distribution among four polymers, although they have different length soft alkylene chains to interlink same rigid backbone carbazole. Gas adsorption isotherms show that H2 storage of polymers can be up to 1.33 wt% at 1.0 bar and 77 K, the uptake capacity for CO2 can reach 16.8 wt% at 1.0 bar and 273 K, CH4 uptake can reach 2.11 wt% at 1.0 bar and 273 K, and the CO uptake performance can be up to 1.37 wt% at 298 K and 1.0 bar. Selective adsorption of CO2/N2 and CO2/CH4 calculated using the initial gas uptake slopes shows that these networks display good selectivity with a maximum value of 47.7 (33.8) and 14 (7.3) at 273 K (298 K). The high selective adsorption performances make these materials potential candidates for gas separation and other environmental applications. image

Novel high band gap pendant-borylated carbazole polymers with deep HOMO levels through direct +NB− interaction for organic photovoltaics

High band gap borylated carbazole polymers of P(3,6-BCBTD) and P(3,6-BCQT) results in high electron affinity and deep HOMO levels, with PCEs of 3.82% and 1.44%.

A novel film of conjugated polymer grafted onto gelatin for detecting nitroaromatics vapor with excellent inhibiting photobleaching

A novel sensing material (Gel-P) based on conjugated carbazole polymer grafted onto gelatin was successfully synthesized by spin-coating way. The grafting reaction between gelatin and Polymer P was confirmed by ATR-FTIR spectra of Polymer P and the content of residual amino group in gelatin solution. After UV irradiation for 30min, the fluorescence intensity of Gel-P only reduced by 7.6%, while the polystyrene film doped with polymer P (Ps+P) decreased by 32.4%, indicating higher capability in inhibiting photobleaching for Gel-P due to the presence of tryptophan in gelatin and the fixation effect of gelatin molecules to polymer chains via hydrogen bonds between amino and hydroxyl. Exposed to saturated DNT vapor, the Gel-P sensor exhibited a high quenching efficiency (Qf) of 60% after 50s and the fluorescence of P in Gel-P film was completely quenched for 300s owing to the plenty of NH2 and OH groups in gelatin, which could effectively absorb nitroaromatics (NACs) by hydrogen bonding interaction between NACs and gelatin. After being exposed to saturated DNT vapor for 300s, the Gel-P sensor showed good reversibility of quenching process.

SYNTHESIS AND CHARACTERIZATION OF POLYCARBAZOL - POLYANILINE COPOLYMER IN DICHLOROMETHANE SOLUTION

Conductive polymers can be synthesized in solution or on the electrode surface by oxidation of aromatic heterocyclic organic molecules. Polypyrrole, polythiophene, polyaniline, polyfuran, polyphenylenevinylene, polytionaphtene, polycarbazole, polyindole and polyazulene are the most well-known conductive polymers. Although less studied among the conductive polymers, carbazole polymers have many advantages such as cheap, environmental and chemically stable because of aromatic structure, optic with nitrogen atom in structure, electrical properties, can give polymers having a lower band gap than p-phenylene polymers because occur from biphenyl group. During the polymerization, poly (2,7-carbazole) derivatives can be obtained by binding from 2- and 7- positions while poly (3,6-carbazole) polymers obtained by binding from 3- and 6- positions. Features and applications area of these polymers are different [1,2]. In previous studies, electrochemical synthesis of Polyaniline was carried out in dichloromethane medium and it was used as modified surface for determination of some phenolic compounds [3,4]. In this study, electropolymerization of polycarbazole- polyaniline (PC - PANI) copolymer was firstly studied using polymerization solution containing dichloromethane / 100 mM tetrabutylammonium perchlorate (TBAP) / 1.0 mM carbazole / 50.0 - 200 mM aniline and optimum polymerization conditions were determined. Aqueous and non-aqueous medium behaviors of prepared PC –PANI modified electrode were investigated. The best electroactive film was determined. Characterization of the synthesized copolymer film was carried out by UV-vis, FT-IR, Raman, SEM and EDS techniques. Electrochemical behavior of hydroquinone was investigated in NaHSO4 / Na2SO4 medium over obtained modified electrode and it was compared with its homopolymers.

Electrochemically generated networks from poly(4,4′-triphenylamine-co-9,9-dioctyl-2,7-fluorene) with grafts containing carbazole groups

Herein, the synthesis of poly(4,4′-triphenylamine-co-9,9-dioctyl-2,7-fluorene) grafted with oligo N-(2-hydroxyethyl) carbazolyl methacrylate as side chains was performed in two steps. A macromonomer with dibromo-triphenylamine end was firstly synthesized by atom-transfer radical polymerization of N-(2-hydroxyethyl) carbazolyl methacrylate followed by Suzuki polycondensation of the macromonomer with 9,9-dioctylfluorene-2,7-diboronic acid. The graft copolymer was characterized by Fourier-transform infrared spectroscopy (FTIR), 1H and 13C-NMR spectroscopy while the optical properties were investigated by UV–vis and fluorescence methods. Cyclic votammetry studies evidenced that the redox processes were accompanied by the dimerization of carbazole pendant groups and polymer crosslinking with the formation of an insoluble network. The parent polymer was post-modified, in solution or bulk, by electrochemical oxidation leading to a crosslinked and insoluble network having electrochromic properties.

A novel synthesis of 4-toluene 9H-carbazole-9-carbodithioate, electropolymerization and impedance study

A novel synthesis of 4-toluene 9H-carbazole-9-carbodithioate (TCzC) was chemically synthesized and character- ized by Fourier Transform Infrared (FTIR), proton nuclear magnetic resonance ( 1 H-NMR), and carbon nuclear magnetic resonance ( 13 C-NMR) spectroscopies. Specific (Csp) and double layer capacitances (Cdl) of the electro-coated poly(car- bazole) and poly(TCzC) films were obtained on glassy carbon electrode (GCE) by impedimetric method with DC potential from -0.1 to +1.0 V by increasing potential of 0.2 V. The polymers were characterized by Cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), Atomic force microscopy (AFM), and Electrochemical impedance spectroscopy (EIS). The use of additional variable (DC potential) helped to disam- biguate the equivalent circuit model of R(C(R(Q(RW))))(CR). Simulation results were compared with experimental data. In this study, substituted group effects of CS2 and tosyl on carbazole polymer were investigated by EIS technique. CS2 group together with tosyl group in the structure of carbazole decreased the specific capacitance value (Csp = 0.43 mF·cm -2 ) com- pared to PCz (Csp = 1.44 mF·cm -2 ). Electropolymerization formation was seriously affected by substituted groups of CS2 and tosyl on conjugation system because of the electron donor and acceptor ability.

Morphology and dispersion of polycarbazole wrapped carbon nanotubes

Using MM3 force-field simulations in combination with optical measurements, we investigate the morphology and dispersion of a variety of single-walled carbon nanotubes (SWNTs) non-covalently functionalized by carbazole polymers. Our results elucidate that isomer types of poly-carbazoles together with their length govern the morphology of carbazole–SWNT hybrids and, hence, their dispersion and bundling properties. The π–π stacking between the carbazole and the SWNT results in a stable carbazole–SWNT hybrid complex with the SWNT–carbazole interaction increasing with a decrease in the polymer length. All oligocarbazoles preferentially bind to larger diameter SWNTs with the strongest interactions observed for the hybrids with 2,7-isomers. While short oligocarbazoles cover only one side of the tube, long 2,7-isomers tend to gradually coil around the entire tube. In contrast, 3,6- and 2,7–3,6-oligocarbazoles irregularly bunch together on a small area of the tube. The small size of carbazole oligomers and their localization on one side of the nanotube prevents tube unbundling, and leads to photoluminescence quenching in SWNTs functionalized by 2,7–3,6-oligocarbazoles.