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This paper aims to investigate the electrochromic (EC) properties of poly(triphenylamine alkyl ether) and poly(triphenylamine aryl ether) in two different electrolyte solution to study the resistive switching behaviour of acid-doped poly(triphenylamine alkyl ether).

By Buchwald–Hartwig coupling reaction, two novel poly[N-p-phenoxy-N-[4-[2-(2-methoxyethoxy)ethoxy]ethoxy]triphenylamineandpoly[N,N-bis(4-phenoxy)]triphenylamine were synthesized from 4-phenoxyaniline and two dibromo aromatic compounds, 1,2-bis[β,β′-(p-bromophenoxy)ethoxy]ethane and bis(4-bromophenyl) ether.

Poly(triphenylamine alkyl ether) displayed excellent EC characteristics, with a coloration change from a colourless neutral state to light blue and red oxidized states, while poly(triphenylamine aryl ether) showed coloration a change from a colourless neutral state to light blue oxidized state in tetrabutylammonium perchlorate electrolyte solution. Moreover, p-toluenesulfonic acid-doped poly(triphenylamine alkyl ether) exhibited a non-volatile bistable resistive switching behaviour with a high high-conductivity/low-conductivity ratio of up to 104, long retention time exceeding 2.5 × 10³ s and the switching threshold voltage was also lower than −2V.

In this paper, the non-volatile bistable resistive switching behaviour of acid-dopedpoly(triphenylamine alkyl ether) was in accordance with the molar ratio of 1:1. The effects of different molar ratios remained to be studied.

Poly(triphenylamine ether)s may find optoelectronic applications as new EC and resistive switching materials.

The effects of alkyl and aryl ether structures in the main chain on the EC and resistive switching behaviour of triphenylamine unit have not yet been reported.

The purpose of this paper was to provide a simple method for the preparation of carbon nanotubes (CNTs) by pyrolysing sunflower seed hulls and sago and to evaluate the application of such CNTs in supercapacitors.

The CNTs were obtained by pyrolysing sunflower seed hulls and sago at 800°C. The prepared CNTs were studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammograms, galvanostatic charge and discharge and electrochemical impedance spectra methods.

The CNTs had large surface areas as determined by the methylene blue method and the Brunauer – Emmett – Teller method. And the CNTs that were prepared by pyrolysing the natural sunflower seed hulls (denoted as CNTs-1) and sago (denoted as CNTs-2) had capacitances of 86.9 F/g and 26.7 F/g, respectively.

The capacitances of CNTs can be further improved.

The exceptional electronic and mechanical properties of CNTs prepared lend the CNTs to diverse applications including electrocatalysts, hydrogen storage, photovoltaic devices actuators, energy storage, field-emitting flat panel displays and composites.

Currently, CNTs have not yet been used in the industry at a mass production scale due to high costs associated. The outcomes of the study reported in this article could provide a convenient method in aid of industrialisation of the production of CNTs.

The purpose of this paper is to improve opening performance of bi-directional rotation gas face seals by investigating the hydrodynamic effect of non-closed elliptical grooves.

A model of non-closed elliptical groove bi-directional rotation gas face seal is developed. The distribution of lubricating film pressure is obtained by solving gas Reynolds equations with the finite difference method. The program iterates repeatedly until the convergence criterion on the opening force is satisfied, and the sealing performance is finally obtained.

Non-closed elliptical groove presents much stronger hydrodynamic effect than the closed groove because of drop of the gas resistance flowing into grooves. Besides, the non-closed elliptical groove presents significant hydrodynamic effect under bi-directional rotation conditions, and an increase of over 40 per cent is obtained for the opening force at seal pressure 4.5 MPa, as same level as the unidirectional spiral groove gas seal. In the case of bi-directional rotation, the value of the inclination angle is recommended to set as 90° presenting a structure symmetry so as to keep best opening performance for both positive and reverse rotation.

A model of non-closed elliptical groove bi-directional rotation gas face seal is established. The hydrodynamic mechanism of this gas seal is illustrated. Parametric investigation of inclination angle and integrity rate is presented for the non-closed elliptical groove bi-directional rotation gas face seal.

The purpose of this paper is to prepare polypyrrolone nanofibres and investigate the effects of concentration of polypyrrolone precursor and voltage on polypyrrolone precursor nanofibres by electrospinning, in order to achieve ideal nanofibres.

Polypyrrolone nanofibres were prepared by polypyrrolone precursor electrospinning. Various fibres were made with different concentrations of polypyrrolone precursor and different voltages. Morphology of fibres was characterised by scanning electron microscopy to study the effect of different preparation conditions on morphology of fibres.

A method of preparation of polypyrrolone nanofibres with the polypyrrolone precursor by electrospinning was introduced which had not been reported. The effects of concentration of polypyrrolone precursor and voltage on the morphology of the nanofibres were studied. It was found that the concentration of polypyrrolone precursor was the major factor and the voltage also affected the distribution and dimension of polypyrrolone fibres to an extent.

Polypyrrolone nanofibres provided potential applications in solar cells and field‐effect transistors.

To the best of the authors' knowledge, there is no literature on the preparation of polypyrrolone nanofibres by electrospinning. Herein the preparation of polypyrrolone nanofibres by electrospinning is first reported. The polypyrrolone nanofibres might be used in solar cell, non‐linear optics, conducting and semi‐conducting materials.

The purpose of this paper is to study the preparation and characterisation of poly(p‐phenylene vinylene), PPV/TiO₂ photoluminescent (PL) nanofibres, and the causes of the blue‐shift in PL spectrum of the as‐prepared composite nanofibres.

A simple method coupling sol‐gel method and electrospinning technology was used to prepare PPV/TiO₂ nanofibres from precursory PPV solution.

Small‐angle X‐ray diffractometer showed that the nano‐TiO₂ was mainly amorphous in composite nanofibres. The PL spectrum of the composite nanofibres confirmed the conclusion that there was a slight blue‐shift in the PL spectrum owing to the existence of TiO₂ nanoparticles.

The nanofibres collected aligned in random orientation, if parallel nanofibres were obtained. Practical applications will be effected.

The electrospinning method provides an effective strategy for preparing polymer composite nanomaterials.

Composite nanofibres will have potential applications for green optical/electric devices such as LEDs, sensors, transducers and flat panel displays.

To evaluate the effect of the concentrations of isocyanate group and hydroxyl group and hydroxyl group species on the rate constants of isocyanate‐propanol reaction, and to reveal the kinetics of isocyanate‐hydroxyl reaction.

The in situ FTIR technique was employed to measure the group concentration evolutions, by which the rate constants were determined. Besides, the FTIR was used to detect the OH absorbance shifts during reaction and the OH absorbance at different concentrations. The kinetic mechanism of isocyanate‐propanol reaction was discussed with the combination of rate constants and FTIR spectra.

A new reaction mechanism, alcohol association mechanism, was proposed that could explain many phenomena. It was revealed that the rate constant was independent of the isocyanate concentration, while the concentration and species of hydroxyl groups had apparent effects on the rate constants. It was possible to calculate the number averaged degree of association of propanol with alcohol association mechanism.

The associated n‐propanol molecules that reacted with isocyanate to form urethane were the associated dimer and trimer predominately, while the iso‐propanol was the dimer.

The kinetics of isocyanate‐hydroxyl reaction and the alcohol association mechanism will be helpful to understand the preparation and curing of polyurethane, and their controls.

A new reaction mechanism, alcohol association mechanism, was proposed that could explain many phenomena that might not be interpreted by other mechanisms. The mechanism could be employed to calculate the number averaged degree of association of alcohols.

To evaluate the competing reaction of isocyanate with cellulose and water which can provide direction for further studies on bonding and curing reactions of isocyanate with wood.

Two modern analytical techniques, Fourier transform infra‐red (FTIR) and X‐ray photoelectron spectroscopy (XPS), were used. The FTIR was used to identify the products of the reaction of phenyl isocyanate (PI) with alcohol, water, and cellulose; while the XPS was used to evaluate the proportions of isocyanate that reacted with water or cellulose when PI reacted with cellulose at different moisture contents (MCs), respectively.

Methods for the IR identifications of reaction results of PI with n‐propanol, water, and cellulose, in which the reactions of PI with water and PI with cellulose resulted in N,N′‐diphenylurea and carbamate, respectively, were developed. It was discovered that the extent of reaction of isocyanate and cellulose decreased with increasing cellulose MC, and 92.98 per cent isocyanate reacted with water when 9.78 per cent MC was reached. It was confirmed that the products of the PI reaction were distributed mainly on the surface of the cellulose particles.

The study only focused on the reaction of PI. However, the industrial isocyanates, e.g. methylene diphenyl diisocyanate (MDI), polymerized methylene diphenyl diisocyanate (p‐MDI) that have complexities in chemical structures and components, make analyses with FTIR and XPS impossible.

The paper provides some instructive information about the isocyanate reaction that will help understanding the characteristics of isocyanate and guiding the design of technology bonding isocyanate to fibre, wood, etc.

The application of FTIR and XPS for evaluating the reaction of isocyanate with cellulose having different MCs was novel and may be used as a reference for other relevant studies.

To evaluate the photoelectrochemical characteristics of polymer doped with CdSe and CdSe/TiO₂ for improved photoelectric conversion efficiency.

A method was set‐up to dope the nano‐CdSe with poly‐perylene‐tetracarboxylic imide (PPI) in the nano‐TiO₂/ITO films, which were characterised by X‐ray diffraction; electrochemical analytical system; multifunctional grating spectrometer; digital photometer and ultrasonic cleanout instrument, etc.

The modification of PPI doped with CdSe and CdSe/TiO₂ showed significant elevation of the monochromatic incident photo‐to‐electron conversion efficiency (IPCE) of the photoelectrode, which was about 3 per cent. The doping caused a tone up separate efficiency of charge, restraining the complex of electron‐cavity by doped nano‐CdSe. Therefore, the photocurrent of the TiO₂ film doped with nano‐CdSe was about three times higher than that without.

The mixed film could also be formed from conjugated polymer mixed with polymer and inorganic particle, based on polymer doped with CdSe and CdSe/TiO₂. In addition, the monochromatic incident IPCE of the photoelectrode needs to be extensively studied.

The treatment method developed provided a practical and effective solution to increasing the ICPE.

The method for doping polymer with CdSe and CdSe/TiO₂ was novel and could probably be adapted for the manufacture of solar cell.

The purpose of this paper is to develop porous nitrogen-enriched carbon (NC-U) with high nitrogen concentration and high specific capacitance (Cpe) as the electrode material for supercapacitors.

NC-U was obtained by carbonization of polyvinylpyrrolidone/melamine formaldehyde resin (PVP/MF) with different contents of urea. In comparison, NC-K was also prepared by the KOH activation method. A series of asymmetric supercapacitors with NC as a negative electrode was assembled. The composition, microstructure and electrochemical properties of NC and their supercapacitors were studied.

The results show that NC-U shows irregular particles with a porous honeycomb structure. High Cpe was obtained for urea-treated NC-U because of the improvement of nitrogen, conductivity and specific surface area (S _BET ). NC-U50 with 13.15 per cent at nitrogen has the highest Cpe of 148.53 F/g because of the highest concentration of N-6 and N-5. NC-K with higher S _BET has lower Cpe than NC-U50 because of its lower nitrogen concentration. When the specific power of the supercapacitor with NC-U50 as a negative electrode is 1,565.56 W/kg, its specific energy is still 4.35 Wh/kg. There is only 5.9 per cent decay in Cpe over 1,000 cycles.

NC-U is a suitable electrode material for supercapacitors, which can be used in the field of electric vehicles to solve the problems of energy shortage and environmental pollutions.

Porous NC-U based on PVP/MF/urea composites with high nitrogen concentration and Cpe is novel, and it owns good electrochemical properties.

The purpose of this paper is to develop nitrogen-enriched carbon (NC) with high conductivity and specific capacitance as electrode materials for supercapacitors.

Graphene oxide (GO) was synthesized by the modified Hummers–Offeman method. NC was synthesized by carbonization of melamine formaldehyde resin/graphene oxide (MF/GO) composites. Supercapacitors based on Ni(OH)2/Co(OH)2 composites as the positive electrode and NC as the negative electrode were assembled. The electrochemical performances of NC and supercapacitors are studied.

The results show that obtained NC has high nitrogen content. Compared to NC-GO0 without GO, high conductivity and specific capacitance were obtained for NC with GO due to the introduction of layered GO. The presence of pseudocapacitive interactions between potassium cations and the nitrogen atoms of NC was also proposed. When the weight ratio of GO to MF is 0.013:1, the obtained NC-GO3 has the highest specific capacitance of 154.07 F/g due to GO and its highest content of N-6. When the P of the asymmetric supercapacitor with NC-GO3 as the negative electrode is 1,326.70 W/kg, its Cps and Ep are still 23.84 F/g and 8.48 Wh/Kg, respectively. There is only 4.4 per cent decay in Cps of the supercapacitor over 1,000 cycles.

NC is a suitable electrode material for supercapacitors. The supercapacitors can be used in the field of automobiles and can solve the problems of energy shortage and environmental pollutions.

NC based on MF/GO composites with high nitrogen content and conductivity was novel and its electrochemical properties were excellent.