Fabrication of Polyaniline/Silver Nanocomposite Under Gamma-ray Irradiation

Polyaniline （PANI）/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, which indicated that PANI and face-centered-cubic silver were synthesized under γ-ray irradiation. The reaction mechanism were discussed, which revealed that the PANI was formed by the reaction of aniline cation radicals formed by the reaction of aniline cation and -OH, and Ag was formed by the reaction of Ag＋ and eaq. The morphology of the composite consisted of PANI nanofibers and Ag nanoparticles, and the mechanism of the morphology formation was discussed, which revealed that the rapid mixing like polymerization process might play an important role. It was revealed that the transport behavior of the composite well fitted with the variable-range-hopping model in 80-300 K and deviated from the model below 80 K.

Orange dye polyaniline composite based impedance humidity sensors

This study presents the fabrication and investigation （PANI） composite films. A blend of 3 wt.% OD with 1 of humidity sensors based on orange dye （OD） and polyaniline wt.% PANI was prepared in 1 ml water. The composite films were deposited on glass substrates between pre-deposited silver electrodes. The gap between the electrodes was 45 um. The sensing mechanism was based on the impedance and capacitance variations due to the absorption/desorption of water vapor. It was observed that with the increase in relative humidity （RH） from 30% to 90%, the impedance decreases by 5.2 × 10^4 and 8.8 × 10^3 times for the frequencies of 120 Hz and 1 kHz, respectively. The impedance-humidity relationship showed a more uniform change compared to the capacitance-humidity relationship in the RH range of 30% to 90%. The consequence of annealing, measuring frequency, response and recovery time, and absorption-desorption behavior of the humidity sensor were also discussed in detail. The annealing resulted in an increase in sensitivity of up to 2.5 times, while the measured response time and recovery time were 34 s and 450 s, respectively. The impedance-humidity relationship was simulated.

Dielectric and Piezoelectric Properties of 0-3 PZT/PVDF Composite Doped with Polyaniline

Lead zirconate titanate （ PZT ） / polyvinylidene fluoride （PVDF） 0-3 piezoelectric composites doped with polyaniline （PANI） were obtained by hot-press method. The polarization properties of the composites were characterized by XRD and P- E hysteresis loops at room temperature. And the dielectric and piezoelectric properties were also measured. The results show that the poling of PZT could be effectively carried oat and the dielectric constant e, and dissipation tanδ increase monatonously by increasing the volume fraction of PANI in the composite. The piezoelectric constant d33, and the planar electromechanical coupling factor kp increase while the mechanical quality factor Qm decreases with the increase in the content of PANI. The d33, kp and Qm show the extremum values at 8 vol%-10 vol% PANI.

Synthesis, Characterization and Electrochemical Behavior of p-NiO/n-TiO_2/Polyaniline Composites

The p-NiO/n-TiO2/polyaniline composites were synthesized via in situ polymerization of aniline. The structure and morphology of the composites were characterized by means of X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Fourier transform infrared spectroscopy（FTIR） and UV-Vis absorption spectroscopy. It was found that the p-n junction p-NiO/n-TiO2 particles were trapped in the polyaniline molecular matrix and the polyaniline was deposited on the surface of the particles to form a kind of flower cluster morphologies. The electrochemical behavior of the polyaniline composites was investigated. The electrochemical reactivity of the polyaniline was influenced by the p-NiO/n-TiO2 particles due to the effect of electron-hole pairs in these p-n junction particles. The reversibility of redox process and current intensity of the polyaniline composites with the changing of potential scan rate were also discussed.

Polyaniline-graphite composite film glucose oxidase electrode

A novel polyaniline-graphite composite film glucose oxidase （PGCF GOD） electrode was developed. The PGCF was synthesized by cyclic voitammetry method in 0.5 mol/L H2SO4 solution containing 1 g/L graphite powder and 0.2 mol/L aniline. The PGCF GOD electrode was prepared by doping GOD into the composite film. The morphology of the PGCF and the response property of the PGCF GOD electrode were investigated by scanning electron microscopy and electrochemical measurement, respectively. The results show that the PGCF has a porous and netty structure and the PGCF GOD electrode has excellent response property such as high sensitivity and short response time. Influences of pH value, temperature, glucose concentration and potential on the response current of the electrode were also discussed. The sensor has a maximum steady-state current density of 357.17μA/cm2 and an apparent Michaelis-Menten constant of 16.57 mmol/L. The maximum current response of the enzyme electrode occurs under the condition ofpH 5.5, 0.8 V and 65℃.

Polyaniline Nanotube-ZnO Composite Materials: Facile Synthesis and Application

Polyaniline nanotubes and PANI-ZnO nanocomposites were prepared by the simplified Template-Free method. The experimental results indicated that the average diameter of Polyaniline nanotubes was approximately 150-200 nm. The average crystallite size of ZnO in PANI-ZnO composites was 27 nm. Moreover, the as-prepared samples were characterized by scanning electron microscopy（SEM）, FT-IR spectroscopy（FTIR） and X-ray diffraction（XRD）. Photocatalytic properties of the obtained samples were investigated by the photodegradation analysis of orange II and methylene orange dye. The as-prepared PANIZnO nanocomposites exhibited much higher photocatalytic activity than pure PANI nanotubes. During 2 h photocatalytic courses under UV irradiation, the degradation ratios of Orange II and methyl orange using PANIZnO nanocomposites were 90.3% and 84.5%, respectively. Furthermore, this method can be extended to prepare other organic-inorganic semiconductor composites based composite catalysts.

Effect of Attapulgite Added in Plating Bath on the Properties of Ni/TiC Nano-composite Coatings

Pure copper plates were coated by Ni-TiC dipulse current plating method. The effects of adding different concentration（ranging from 0.5 g/L to 3.0 g/L） of attapulgite nano particles to the plating bath on the surface morphology, wear resistance, and oxidation resistance of Ni/TiC/Attapulgite nano-composite coatings were investigated. The experimental results show that the composite coating is flat and compact with adding 3.0 g/L in the bath, and the coating preferred orientation is changed from the planes（111） to（200）. The coefficient of the composite coatings decreases from 0.68 to 0.18 with increasing content of attapulgite in the bath, a mixed mode of adhesive-abrasive wear occurs for all coatings, and the wear mechanism shows a transition from adhesive-abrasive to predominantly abrasive wear mechanism when the concentration of attapulgite is beyond 1.5 g/L in electrolyte. The oxidation resistance of composite coatings is the best prepared when adding attapulgite particles at 0.5 g/L in the bath, the oxide mainly consists of a NiO phase by X-ray analysis.

Structural and electrical properties of HCl–polyaniline–Ag composites synthesized by polymerization using Ag-coated (NH_4)_2S_2O_8 powder

Ag nanoparticles were sputter-deposited on ammonium persulfate((NH_4)_2S_2O_8) powder to obtain(NH_4)_2S_2O_8-Ag powder, which was used to synthesize the HCl-doped polyaniline-Ag(HCl-PANI-Ag) composite via a polymerization procedure. The Ag nanoparticles were dispersed in the HCl-PANI matrix, and their sizes mainly ranged from 3 to 6 nm. The Ag nanoparticles did not affect the structure of emeraldine salt in the composite, and they increased the ordered crystalline regions in the HCl-PANI matrix. The HCl-PANI-Ag composite had a conductivity of(6.8 ± 0.1) S/cm, which is about four times larger than that of the HCl-PANI. The charge transport mechanism in the composite is explained by the three-dimensional Mott variable-range hopping(3D-Mott-VRH).

HYBRID AND CHARACTERISTIC OF POLYANILINEBARIUM TITANATE NANOCOMPOSITE PARTICLES

Polyaniline-barium titanate (PAn-Ba-TiO3) ultrafine composite particles were prepared by the oxidative polymerization of aniline with H2O2 while barium titanate nanoparticles were synthesized with a sol-gel method. The infrared spectrogram shows that the polymerization of PAn in the hybrid process of PAn-BaTiO3 is similar with the polymeric process of pure aniline, and there is interaction of PAn and BaTiO3 in the PAn-Ba-TiO3. SEM and TEM results show that the average diameter of the composite particles is 1.50μm and the diameters of BaTiO3 nanoparticles are 5 - 15 nm in the composite particle. The electrical conductivity of the ultrafine com-posite particles is transformable from 10°to 10-11S/cm by equilibrium doping or dedoping method using various concentration of HCl or NaOH solutions.

Synthesis and electrochemical properties of three-dimensional graphene/polyaniline composites for supercapacitor electrode materials

To improve the specific capacitance and rate capability of electrode material for supercapacitors, a three-dimensional graphene/polyaniline （3DGN/PANI） composite is prepared via in situ polymerization on GN hydrogel. PANI grows on the GN surface as a thin film, and its content in the composite is controlled by the concentration of the reaction monomer. The specific capacitance of the 3DGN/PANI composite containing 10 wt% PANI reaches 322.8 F.g-1 at a current density of 1 A.g-1, nearly twice as large as that of the pure 3DGN （162.8 F.g-1）. The capacitance of the composite is 307.9 F.g-1 at 30 A.g-1 （maintaining 95.4%）, and 89% retention after 500 cycles. This study demonstrates the exciting potential of 3DGN/PANI with high capacitance, excellent rate capability and long cycling life for supercapacitors.

Preparation and Properties of Polyaniline Composite Films

Polyaniline (PAn) was synthesized by chemical oxidation polymerization. The conductive polymer doped by camphor sulfonic acid (CSA) and a matrix polymer, polyamide66, polyamide1010 or polyamide11, were dissolved in m-cresol and the blend solution was cast in a glass and dried for preparing polyaniline composite films. Conductivity was from 10 -6 to 10 0 Ω -1 ·cm -1 with different weight fraction of PAn-CSA. The crystallization of the films was studied by means of differential scanning calorimeter (DSC). The treatment of the composite films in different pH value solution would result in decrease of conductivity, especially in an alkaline solution.

Lead removal from aqueous medium using fruit peels and polyaniline composites in aqueous and non-aqueous solvents in the presence of polyethylene glycol

In the present study,composites of Polyaniline and some fruit peels were synthesized in various conditions and used for lead removal from aqueous solutions.Adsorption tests were conducted in batch mode using the most efficient adsorbent,and the effects of medium pH,initial lead concentration,contact time,adsorbent dosage,and adsorption isotherms were investigated.The results showed that all composites were more efficient in lead removal compared to the fruit peels alone.The highest removal percentage was related to the composite of banana peel and Polyaniline that synthesized in the aqueous solution in the presence of 2 g·L^(-1) Poly ethylene glycol.This composite showed 95.96%lead adsorption at pH=6,the contact time of 90 min,the initial lead concentration of 25 mg·L^(-1),and an adsorbent concentration of 8 g·L^(-1).Adsorption isotherm study showed that adsorption of lead by synthesized composite could be fitted by both Langmuir and Freundlich models,but the Langmuir model was more fitted than Freundlich.Besides,some characteristics of the composites,such as chemical composition(XRD analysis),structure,and morphology(SEM analysis)and functional groups(FTIR analysis),were studied.

Thermoelectric properties of Bi_(0.5)Sb_(1.5)Te_3/polyaniline composites prepared by mechanical blending and in-situ polymerization

Bi 0.5 Sb 1.5 Te 3/polyaniline composites were prepared by mechanical blending and in situ polymerization, and their transport properties were measured. It was found that for the composites with 1%, 3%, 5% and 7% polyaniline (mass fraction) respectively, which were prepared by mechanical blending, the power factors decrease by about 30%, 50%, 55% and 65% compared with the Bi 0.5 Sb 1.5 Te 3 samples, which is mainly due to the remarkable decreases of the electrical conductivity. The electrical conductivity and power factor of the composites samples with 7% polyaniline prepared by in situ polymerization are higher by about 65% and 60%, respectively, than that of the corresponding samples prepared by mechanical blending.

Electroanalytical studies on electrically conductive polyaniline： Nylon-6,6 composite film

Electrically conductive composite films ofpolyaniline and nylon-6.6 are prepared by diffusing aniline followed by oxidative polymerization of aniline into nylon-6.6 matrix. In order to determine the diffusion coefficient for the chloride ion diffusion into the composite matrix electrochemically, galvanostatic pulse method is used and the diffusion coefficient is estimated to be -6.48× 10^-17 cm^2s^-1. The results are discussed in view of them being potential replacement materials for battery. electrodes and sensors devices.

Synthesis of nitrogen-doped reduced graphene oxide/magnesium ferrite/polyaniline composite aerogel as a lightweight,broadband and efficient microwave absorber

The fabrication of graphene-based microwave absorbing materials with low density,small filling ratio,broad bandwidth and strong absorption remains a huge challenge.In this work,nitrogen-doped reduced graphene oxide/magnesium ferrite/polyaniline(NRGO/MgFe_(2)O_(4)/PANI)composite aerogel was synthesized by a three-step method of solvothermal reaction,in situ chemical oxidation polymerization and hydrothermal self-assembly.The results showed that the obtained aerogels had a unique three-dimensional(3D)porous network structure and low bulk density(11.1-13.0 mg cm^(−3)).It was worth noting that in the NRGO/MgFe_(2)O_(4)/PANI ternary composite aerogel,MgFe_(2)O_(4)coated with a thin PANI layer was anchored on the surface of NRGO sheets.Furthermore,the NRGO/MgFe_(2)O_(4)/PANI ternary composite aerogel showed much better microwave absorbing capacity compared with pure NRGO aerogel and NRGO/MgFe_(2)O_(4)binary composite aerogel.When the filling ratio was as low as 11.5 wt.%,the obtained ternary composite aerogel exhibited the maximum effective absorption bandwidth of 7.0 GHz at a matching thickness of 2.1 mm,and the minimum reflection loss of-42.9 dB at a thickness of 3.57 mm.Additionally,the prob-able microwave dissipation mechanism was also elucidated.It was believed that this study would pave the way for the construction of 3D graphene-based composites as lightweight,broadband and efficient microwave absorbents.

聚丙烯酰胺凹凸棒土(Attapulgite)纳米复合高吸水性树脂的制备与性能

Organo-attapulgite was obtained by modifying attapulgite with hexadecyltrimethyl ammonium bromide.A new organo-attapulgite based superabsorbent composite was prepared by polymerization of organo-attapulgite dispersed acrylamide,using N,N′-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator.The structure,morphology,thermal stability of organo-attapulgite and the composite were characterized by FTIR,XRD,SEM,TEM and TGA,respectively.The results indicated that a nanocomposite was successfully obtained after incorporating organo-attapulgite into the polyacrylamide network.The thermal stability and water absorbency of the nanocomposite were improved greatly after the organification of attapulgite.Water absorbencies for the nanocomposite incorporated with 10 wt% HDTMA-APT in distilled water and in a 0.9 wt% NaCl solution were 2803 g g -1 and 121 g g -1,respectively.

Preparation and electrochemical characterization of C/PANI composite electrode materials

Taking the nano-sized carbon black and aniline monomer as precursor and （NH4）2S2O6 as oxidant, the well coated C/polyaniline（C/PANI） composite materials were prepared by in situ polymerization of the aniline on the surface of well-dispersed nano-sized carbon black for supercapacitor. The micro-structure of the C/PANI composite electrode materials were analyzed by SEM. The electrochemical properties of C/ PANI and PANI composite electrode were characterized by means of the galvanostatic charge-discharge experiment, cyclic voltammetric measurement and impedance spectroscopy analysis. The results show that by adding the nano-sized carbon black in the process of chemical polymerization of the aniline, the polyaniline can be in situ polymerized and well-coated onto the carbon black particles, which may effectively improve the aggregation of particles and the electrolyte penetration. What’s more , the maximum of specific capacitance of C/PANI electrode 437.6F·g -1 can be attained. Compared with PANI electrode, C/PANI electrode shows more desired capacitance characteristics, smaller internal resistance and better cycle performance.

Alginate Composite Hydrogel Bead with Multilayer Flake Structure for Dye Adsorptions

With the rapid development of textile industry,a large amount of dye-contaminated effluents was produced and caused serious environmental problem.To remove the dye from effluents,adsorption materials have been applied because of their relatively cheap,high efficiency,and easy handling.In this study,a novel composite hydrogel bead with unique multilayer flake structure was fabricated by alginate,acrylamide and attapulgite for dye adsorption.Acrylamide was grafted polymerization onto alginate to obtain alginate-g-poly(acrylamide).Then alginate-g-poly(acrylamide)was cross-linked by Ca2+ions in present of attapulgite to form composite hydrogel bead.Scanning electron microscopy(SEM)results show that the freeze dried composite hydrogel bead has multilayer flake structure incorporating attapulgite.Fourier transform infrared spectroscopy(FTIR)and Thermo-gravimetric analysis(TGA)results indicate that acrylamide has been successfully grafted polymerization on sodium alginate.Grafting polymerization of acrylamide onto sodium alginate obviously enhances the swelling of hydrogel bead.Incorporating of attapulgite into hydrogel bead effectively enhances the adsorption capacity to methylene blue and the maximum adsorption capacity is 155.7 mg g-1.Multilayer flake structure increases the adsorption area for methylene blue,but hinders the diffusion of methylene blue into the inner of composite hydrogel bead.High pH solution is beneficial to the adsorption.Pseudo-second order model and Fraundlinch model best describe the adsorption kinetic and isotherm,respectively.These results indicate that composite hydrogel bead is a promising adsorption material for dye-contaminated water treatment.

Thermal Oxidative Degradation and Ageing Performance of Silicone Rubber Filled with Attapulgite

The natural attapulgite(NAPT)was disaggregated by high-pressure homogenization technology combined with extrusion process to prepare the attapulgite with disaggregated rod crystal bundles(DAPT)and large specific surface area of 133.7 m^(2)/g.NAPT and DAPT were incorporated into the silicone rubber to obtain the composite NAPTSR and DAPT-SR by mechanical blending method,respectively.After thermal oxidative ageing at 300℃ for 0.5 h,temperature for the 5%weight loss increased greatly from 385℃ of the neat silicone rubber to 396-399℃ with addition of NAPT and DAPT.NAPT and DAPT enhanced the interaction between the filler nanoparticles and rubber matrix thus inhibited the nanoparticle agglomeration.The conservation rate of the side methyl group in NAPT-SR and DAPT-SR was greatly improved after ageing.Therefore,the thermal oxidative degradation and ageing performance of the silicone rubber composites was significantly reinforced.Moreover,DAPT could greatly restrain the growth of nanoparticles after ageing.Therefore,DAPT-SR showed the better retention of tensile strength(40.6%),elongation at break(34.9%)and tear strength(30.1%)compared with the corresponding mechanical properties of the neat silicone rubber(10.6%,7.4%,and 5.0%)after ageing.