Polyaniline/CuCl nanocomposites prepared by UV rays irradiation

In present paper, polynailine (PANI)/CuCl nanocomposites were prepared by UV rays irradiation method. In this method, photons in the UV rays and Cu²⁺ ions replaced conventional oxidant such as ammonium persulfate (APS) to promote polymerization of aniline monomer. The PANI/CuCl nanocomposites were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscope (HRTEM), and electron diffraction (ED). The results indicated that aniline could polymerize to PANI by UV rays irradiation. Meanwhile, the results of HRTEM and ED confirmed that the CuCl dispersed into PANI was single crystal with cubic crystal structure. A potential formation mechanism of PANI/CuCl nanocomposites was investigated and suggested.     

Studies on preparation and properties of the multi-walled carbon nanotubes (MWNTs)/epoxy nanocomposites

The MWNTs were coated with polyaniline (PANI) by in situ chemical oxidation polymerization method. FTIR spectroscopy, scanning electron microscope (SEM) and X-ray diffraction (XRD) indicated that the MWNTs were coated with PANI. The MWNTs/epoxy nanocomposites were fabricated by using the solution blending method. Differential scanning calorimetry (DSC), tensile testing, HP 4294A impedance analyzer and SEM were used to investigate the properties of the nanocomposites. The results showed that the modified carbon nanotubes were well dispersed in the polymer matrix. The nanocomposites have enhancements in mechanical, thermal and dielectric properties compare with the neat epoxy resin. The nanocomposites were proven to be a good polymer dielectric material.     

MWNTs/PANI composite materials prepared by in-situ chemical oxidative polymerization for supercapacitor electrode

Multi-walled carbon nanotubes (MWNTs)/polyaniline (PANI) composite materials were prepared by in-situ chemical oxidative polymerization of an aniline solution containing well-dispersed MWNTs. The supercapacitive behaviors of these composite materials were investigated with cyclic voltammetry (CV), charge–discharge tests, and ac impedance spectroscopy, respectively. The composites based on the charge-transfer complex between well-dispersed MWNTs and PANI matrixes show much higher specific capacitance, better thermal stability, lower resistance, and were more promising for applications in supercapacitors than a pure PANI electrode. The highest specific capacitance value of 224 Fg⁻¹ was obtained for the MWNTs/PANI composite materials containing MWNTs of 0.8 wt%. The improvement mechanisms of the capacitance of the composite materials were also discussed in detail.     

Nanofibrous TiO2-core/conjugated polymer-sheath composites: synthesis, structural properties and photocatalytic activity

Nanofibrous TiO2-core/conjugated polymer-sheath composite nanocables were synthesized by in-situ chemical oxidative polymerization of aniline with oxidant in the presence of TiO, nanofibers prepared through an electrospinning process. During the polymerization process, aniline molecules were adsorbed on the surface of TiO2. Upon the addition of oxidant, the polymerization of aniline takes place on the surface of the TiO2 nanofibers and polyaniline (PANI) is gradually deposited on their surface. The resulting TiO2-PANI nanocomposites have a coaxial nanocable structure. The morphological and structural properties of the composite nanocables were analyzed by using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) and UV-visible spectroscopy (UV-vis), respectively. The HRTEM images proved that PANI (20 nm thickness) covered the surface of the TiO2 nanofibers. Also, the photocatalytic activity for the degradation of organic dyes on fibrous photocatalysts under UV-light was studied. The photocatalytic experiments showed that dye could be degraded more efficiently on the TiO2-PANI composite nanocables than on pure TiO2, due to the charge transfer from PANI to TiO2. The method for the synthesis of these unique structured composite nanocables is simple, rapid and reproducible. This facile method may be developed to produce multifunctional nanocomposites of various polymers with metal oxide fibers on a large scale for various technological applications such as sensors, solar cells, and catalysts.     

聚苯胺/银纳米复合材料的形貌对抗菌性能的影响

采用快速混合的方法一步原位合成了不同形貌的聚苯胺/银纳米复合材料。扫描电子显微镜证明,通过改变苯胺与硝酸银的物质的量比可使聚苯胺/银纳米复合材料的形貌由微球到纳米纤维的转变。X射线衍射分析表明,单质银的粒径随着苯胺与硝酸银的物质的量浓度比的减小而增大,聚苯胺仍保持特有的非晶态。紫外-可见光谱分析表明,银纳米粒子与聚苯胺分子间存在相互作用,且银粒子改变了聚苯胺的分子结构。抗菌性实验证明,聚苯胺/银纳米复合材料的形貌对抗菌性能有显著影响,聚苯胺/银纳米纤维有最优异的抗菌性能。     

Synthesis and characterization of polyaniline nanorods/Ce(OH)3-Pr2O3/montmorillonite composites through reverse micelle template

Polyaniline (PANI) nanorods/Ce(OH)₃-Pr₂O₃/montmorillonite (MMT) nanocomposites were synthesized via in situ polymerization of aniline monomer through reverse micelle template (RMT) in the presence of montmorillonite and Ce(OH)₃, Pr₂O₃. In the experiment, sulphosalicylic acid was used as dopant, aniline was designated as oil phase and the aqueous solution comprising Ce³⁺ and Pr³⁺ as water phase. The nanocomposites were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy and thermogravimetry-differential thermal analysis (TG-DTA). The results showed that PANI nanorods were synthesized in the interlayer spaces of MMT with uniform spherical rare earth nanoparticles. The thermal stability of the nanocomposites prepared was enhanced drastically compared with pure polyaniline.     

Structural and magnetic properties of nanocomposites based on nanostructured polyaniline and titania nanotubes

Nanocomposites consisting of self-assembled polyaniline (PANI) nanostructures and titania nanotubes (TiO₂-NT) were synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate in an aqueous dispersion of TiO₂-NT (outer diameter ~10 nm), without added acid. The influence of initial mole ratio of aniline to TiO₂ (80, 20, and 5) on the morphology, electrical conductivity, molecular structure, crystallinity, and magnetic properties of synthesized PANI/TiO₂ nanocomposites was studied. Transmission electron microscopy, Raman spectroscopy, and X-ray powder diffraction proved that the shape and structure of TiO₂-NT in the final nanocomposites were preserved. The shape of PANI nanostructures formed in the nanocomposites was influenced by the initial aniline/TiO₂-NT mole ratio. Nanotubes and nanorods are predominant PANI nanostructures in the nanocomposite prepared with the highest aniline/TiO₂ mol ratio of 80. The decrease of aniline/TiO₂ molar ratio induced more pronounced formation of nanorod network. The electrical conductivity of PANI/TiO₂ nanocomposites was in the range (1.3–2.4) × 10^?3 S cm^?1. The nanocomposites exhibit weak ferromagnetic behavior. Approximately order of magnitude lower values of coercive field and remanent magnetization were obtained for nanocomposite samples in comparison to pure PANI.     

Influence of dopant in the synthesis, characteristics and ammonia sensing behavior of processable polyaniline

Polyaniline (PANI) was synthesized by oxidative polymerization of aniline as well as aniline hydrochloride by ammonium persulfate in the presence of para-toluene sulfonic acid (PTSA). This helped in direct usage of the conducting PANI solution for film casting and use as a device for ammonia gas sensing. Viscosity change with applied shear rate was measured for both the polymers. Solid PANI powder was isolated from its tetrahydrofuran solution by using methanol as non-solvent. Thermogravimetric analysis investigated the thermal properties of the solid PANI salts. Elemental analysis of both PANI synthesized in presence of PTSA and PANI synthesized in presence of HCl and PTSA was investigated. A thin coherent film of both the conducting PANI were deposited on glass slides precoated with poly vinyl alcohol (PVA) crosslinked with maleic acid (MA) and was directly used in the sensor device. The morphology of the deposited films was analyzed by scanning electron micrograph. The films were further characterized by Attenuated total reflectance Fourier transformed infrared spectroscopy, ultra violet-visible spectroscopy and X-ray diffraction analyses. Finally, both the doped PANI films on MA crosslinked PVA coated glass slides were used to measure the conductivity and ammonia gas-sensing characteristics.     

Simultaneous synthesis of polyaniline nanorods and magnetite nanoparticles via self-assembly method

In this work, polyaniline (PANI) nanorods and magnetite (Fe₃O₄) nanoparticles have been synthesised by using ammonium persulphate as oxidant via in-situ chemical oxidative polymerisation of aniline in presence of excess of organic sulphonic acid. The resulting PANI/Fe₃O₄ nanocomposites materials were characterised using X-ray diffraction, UV-visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, vibrating sampling magnetometer and thermogravimetric analysis. Spectroscopic results indicated the successful formation of PANI/Fe₃O₄ nanocomposites. As obtained, PANI/Fe₃O₄ nanocomposites have Fe₃O₄ particle size in the range of 3.2–7?nm. Morphologies of PANI/Fe₃O₄ nanocomposites were found to be dependent on the molar ratio of aniline to organic acid. Under certain polymerisation conditions, PANI rods like structures were obtained. PANI/Fe₃O₄ nanocomposites have superparamagnetism and higher thermal stability.     

Electrochemical fabrication of polyaniline/multi-walled carbon nanotube composite films for electrooxidation of methanol

Polyaniline (PANI)/multi-walled carbon nanotubes (MWNTs) composite films were fabricated by electropolymerization of aniline containing well-dissolved MWNTs. The films can be used as catalyst supports for electro-oxidation of methanol. Cyclic voltammogram and Chronoamperogram results show that platinum particles deposited on PANI/MWNT composite films exhibit higher electrocatalytic activity towards methanol oxidation than that deposited on pure PANI films. The porous structure and electrical conductivity of PANI films has been significantly changed by introduction of MWNTs, higher surface areas of PANI/MWNT composites has been achieved therefore. It favors for platinum particles to be highly dispersed on the PANI/MWNT composite films and the better electrocatalytic activity of Pt/PANI/MWNT electrode is induced consequently.     

PANI/CeO_2纳米复合纤维材料的合成和表征

用水热法制备了纳米CeO2,并利用其氧化性通过原位聚合法制备出PANI/CeO2复合纳米纤维。采用X射线衍射(XRD)、扫描电镜(SEM)、红外光谱(FT-IR)等检测技术对复合材料的结构进行了表征。结果表明:复合材料两相间存在化学键合作用;酸浓度和无机纳米相影响了聚苯胺纤维结晶。当CPANI0.1mol/L,随着酸浓度的升高,PANI/CeO2的结构形态从球状逐渐发展成纤维状,CeO2粒子的粒径会影响聚苯胺结晶状态,粒径越小,越易形成结晶规整的纤维结构。     

Free-standing TiO<Subscript>2</Subscript>–SiO<Subscript>2</Subscript>/PANI composite nanofibers for ammonia sensors

Free-standing TiO₂–SiO₂/polyaniline (TS/PANI) composite nanofibers were prepared by electrospinning, in situ polymerization and calcination method. The effect of tetra-n-butyl titanate (TBT) in the electrospinning solution on the morphology and the ammonia sensing properties of TS/PANI composite nanofibers were investigated. The obtained nanofibers were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, thermo-gravimetric analysis and gas sensor test system. It is proved that too much TBT in the solution would make the fibrous morphology and ammonia sensing properties worse. Gas sensing tests showed that the TS/PANI composite nanofibers ammonia sensor can work at room temperature and possess ideal response values, selectivity and repeatability. With the increase in TiO₂ content in the TS nanofibers, the ammonia sensing properties were improved because of the increase in P–N heterojunctions formed between TiO₂ and PANI in the sensors.     

Synthesis and characterization of polyaniline/MCM-41 nanocomposites and their photocatalytic activity

The novel organic-inorganic nanocomposites were synthesized via in-situ polymerization of polyaniline (PANI) with mesoporous silica (MCM-41) for methylene blue (MB) dye degradation under visible light. The synthesized PANI/MCM-41 nanocomposites were characterized through Fourier transform infrared (FTIR), X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), and UV-visible studies. The structural and optical properties confirmed the interaction between PANI and MCM-41. The photocatalytic experiments showed that the MB dye was efficiently degraded by approximately 70% under light irradiation over the surface of the PANI/MCM-41 nanocomposites. The degradation might occur due to the efficient charge separation of the e(-)-h+ pairs at the interface of PANI and MCM-41 in the excited state under light irradiation.     

Preparation and characterization of soluble and DBSA doped polyaniline grafted multi-walled carbon nanotubes nano-composite

Soluble and highly doped polyaniline (PANI) grafted multi-walled carbon nanotubes (MWNTs) nano-composite was synthesized by in situ oxidation polymerization, de-doping with ammonium hydroxide and doping the PANI-Emeraldine base (PANI-EB) grafted MWNTs nano-composite in N-methyl-2-pyrrolidinone (NMP) with Dodecyl benzene sulfonic acid (DBSA). Transmission electron microscope (TEM), Raman spectra, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and standard four-probe methods were employed to characterize morphology, chemical structure and electronic conductivity of the nano-composite. The results show that oxidized phenylamine groups of phenylamine groups contained MWNTs (p-MWNTs) initiate PANI polymerization on the surface of p-MWNTs. PANI coatings graft on the surface of p-MWNTs via amide bond forming homogeneous core (p-MWNTs)–shell (PANI) nano-structures. After doping PANI-EB grafted MWNTs nano-composite with DBSA, the attachment of soluble DBSA doped PANI chains on the surface of p-MWNTs via covalent bonding renders p-MWNTs compatible with polymer matrix and lead to DBSA doped PANI grafted MWNTs nano-composite soluble and stable in NMP. Owing to incorporation of p-MWNTs and chemical bridges between p-MWNTs and PANI chains, conductivity of DBSA doped PANI grafted MWNTs nano-composite at room temperature is increased by about two orders of magnitude over neat DBSA doped PANI.     

SDBS对聚苯胺/氧化镝复合材料性能的影响

采用乳液原位聚合法,合成了十二烷基苯磺酸钠(SDBS)掺杂的聚苯胺(PANI)/氧化镝(Dy2O3)复合材料(PANI/Dy2O3).通过X射线光电子能谱(XPS)、红外光谱(FTIR)、X射线衍射(XRD)、激光粒度分析、塔菲尔曲线(Tafel)和交流阻抗谱(EIS)等手段,表征了在一定的合成条件下,SDBS与苯胺(An)摩尔比(n(SDBS)/n(An))的改变对PANI/Dy2O3复合物的结构、结晶性、粒度及其防腐性能等的影响.实验结果表明,通过Dy2O3对PANI的复合,聚苯胺在复合涂层中所需用量也大为减少(从25%减少到10%),且聚苯胺涂层的防腐性能提高了一个数量级(腐蚀电位从-0,1684V提高到-0,0153V);而且当,n(SD-BS)/n(An)为0.8时,PANI/Dy2O3复合材料的平均粒径和分子规整性较佳,PANI/Dy2O3复合涂层的腐蚀电位最大(-0.0153V),塔菲尔斜率最小(3.918),膜电阻最大(7.5916MΩ),防腐性能最佳.     

Enhancement of electroconductivity of polyaniline/graphene oxide nanocomposites through in situ emulsion polymerization

The present study introduces a systematic approach to disperse graphene oxide (GO) during emulsion polymerization (EP) of Polyaniline (PANI) to form nanocomposites with improved electrical conductivities. PANI/GO samples were fabricated by loading different weight percents (wt%) of GO through modified in situ EP of the aniline monomer. The polymerization process was carried out in the presence of a functionalized protonic acid such as dodecyl benzene sulfonic acid, which acts both as an emulsifier and protonating agent. The microstructure of the PANI/GO nanocomposites was studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV–Vis spectrometry, Fourier transform infrared, differential thermal, and thermogravimetric analyses. The formed nanocomposites exhibited superior morphology and thermal stability. Meanwhile, the electrical conductivities of the nanocomposite pellets pressed at different applied pressures were determined using the four-probe analyzer. It was observed that the addition of GO was an essential component to improving the thermal stability and electrical conductivities of the PANI/GO nanocomposites. The electrical conductivities of the nanocomposites were considerably enhanced as compared to those of the individual PANI samples pressed at the same pressures. An enhanced conductivity of 474 S/m was observed at 5 wt% GO loading and an applied pressure of 6 t. Therefore, PANI/GO composites with desirable properties for various semiconductor applications can be obtained by in situ addition of GO during the polymerization process.     

Effect of different carbon fillers and dopant acids on electrical properties of polyaniline nanocomposites

Electrically conducting nanocomposites of polyaniline (PANI) with carbon-based fillers have evinced considerable interest for various applications such as rechargeable batteries, microelectronics, sensors, electrochromic displays and light-emitting and photovoltaic devices. The nature of both the carbon filler and the dopant acid can significantly influence the conductivity of these nanocomposites. This paper describes the effects of carbon fillers like carbon black (CB), graphite (GR) and muti-walled carbon nanotubes (MWCNT) and of dopant acids like methane sulfonic acid (MSA), camphor sulfonic acid (CSA), hydrochloric acid (HCl) and sulfuric acid (H₂SO₄) on the electrical conductivity of PANI. The morphological, structural and electrical properties of neat PANI and carbon–PANI nanocomposites were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT–IR), UV–Vis spectroscopy and the four-point probe technique, respectively. Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) studies were also conducted for different PANI composites. The results show that PANI and carbon–PANI composites with organic acid dopants show good thermal stability and higher electrical conductivity than those with inorganic acid dopants. Also, carbon–PANI composites generally show higher electrical conductivity than neat PANI, with highest conductivities for PANI–CNT composites. Thus, in essence, PANI–CNT composites prepared using organic acid dopants are most suitable for conducting applications.     

Synthesis of polyaniline/ZrO<Subscript>2</Subscript> nanocomposites and their performance in AC conductivity and electrochemical supercapacitance

Polyaniline/zirconium oxide (PANI/ZrO₂) nanocomposites have been synthesized by incorporating ZrO₂ nanoparticles into the PANI matrix via liquid–liquid interfacial polymerization method. The composite formation and structural changes in PANI/ZrO₂ nanocomposites were investigated by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). PXRD pattern of PANI/ZrO₂ nanocomposites exhibited sharp and well-defined peaks of monoclinic phase of ZrO₂ in PANI matrix. SEM images of the composites showed that ZrO₂ nanoparticles were dispersed in the PANI matrix. The FT-IR analysis revealed that there was strong interaction between PANI and ZrO₂. AC conductivity and dielectric properties of the nanocomposites were studied in the frequency range, 50–10⁶ Hz. AC conductivity of the nanocomposites obeyed the power law indicating the universal behaviour of disordered media. The nanocomposites showed high dielectric constant in the order of 10⁴, which could be related to dielectric relaxation phenomenon. Further, the materials were checked for their supercapacitance performance by using cyclic voltammetry (CV), chronopotentiometry (CP) and electrochemical impedance spectroscopy (EIS). Among the synthesized nanocomposites, PANI/ZrO₂-25 wt.% showed a higher specific capacitance of 341 F g^?1 at 2 m Vs^?1 and good cyclic stability with capacitance retention of about 88% even after 500 charge–discharge cycles.     

Fe2O3/TNTs纳米复合材料的生物合成及其光催化性能研究

采用Shewanellaoneidensis MR-1合成Fe₂O₃/TNTs纳米复合材料,通过高分辨透射电子显微镜、扫描电子显微镜、X射线衍射仪、X射线光电子能谱仪、紫外-可见分光光度计等对Fe₂O₃/TNTs的结构和性能进行表征。结果表明,Fe₂O₃成功负载在TiO₂纳米管上;在紫外光照射下,Fe₂O₃/TNTs在60min内对苯胺蓝的脱色率可达到97.5%,表现出较好的光催化活性。Shewanellaoneidensis MR-1协同Fe₂O₃/TNTs纳米复合材料对苯胺蓝脱色率较So.neidensis MR-1提高了1.63%。     

Synthesis and electrocatalytic activity of multi-walled carbon nanotubes/Cu–Ag nanocomposites

Cu–Ag bimetallic nanoparticles with atomic ratio of 2.1:1 and diameter in the range of 15–30 nm were decorated on acid-treated multi-walled carbon nanotubes by a chemical reduction method, which was characterized by transmission electron microscope (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM). The Cu–Ag/MWNTs nanocomposites were used to construct a modified electrode toward biosensing of H₂O₂ with a high sensitivity. The catalytic ability of MWNTs/Cu–Ag toward H₂O₂ was much better than that of MWNTs/Cu and MWNTs/Ag, which indicated that there is a cooperation effect between Cu and Ag.