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1.
Nylon-6/flake graphite (FG) composite, Nylon-6/graphene intercalation compounds (GIC) composite and Nylon-6/exfoliated graphite (EG) composite were prepared by FG, GIC, EG and caprolactam via in situ polymerization, and the volume resistivities of Nylon-6/flake graphite derivatives composites were also investigated. Meanwhile, the structure of Nylon-6/EG composite was characterized and the thermal stability of Nylon-6/EG composite was investigated as well. When the mass percents of FG, GIC and EG were 1%, 2–4% and 1%, the volume resistivities of flake graphite derivatives composites would reach 7.5 × 10 6 Ω cm, 3.6 × 10 8–1.4 × 10 6 Ω cm and 2.3 × 10 6 Ω cm. When the mass percent of EG increases from 0% to 9%, the thermal stability temperature of Nylon-6/EG composite would enhance from 70 to 196 °C. This shows that Nylon-6/flake graphite derivatives composites can have the antistatic property and thermal stability synchronously. 相似文献
2.
Nylon-6/exfoliated graphite (Nylon-6/EG) composite was prepared via a combination method of in situ polymerization and thermal
expansion and characterized via scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray
diffraction (XRD). Otherwise, the resistivity value of Nylon-6/EG composite was measured, and the volume resistivity value
was calculated as well as. The characterization showed that Nylon-6/EG composite had the morphology of the graphite worm and
was structured by EG and Nylon-6, which covered on the surface of EG. The result exhibited that the volume resistivity of
Nylon-6/EG composite would decrease when the dosage of EG increased. When the mass percent of EG was 1%, the the volume resistivity
value of Nylon-6/EG composite could reach 2.3 × 10 6 Ω cm. This shows that the combination method not only is very effective and reliable but also can play an important role
in preparing antistatic Nylon-6 composite. 相似文献
3.
A series of conducting polyaniline/expanded graphite (PA/EG) composite was synthesized by in situ polymerization of aniline
in acid medium followed by the addition of expanded graphite in various proportions (1, 2 and 3 wt%). The synthesized samples
were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, ultraviolet–visible
absorption, X-ray diffraction and by electrical conductivity measurements. The dc electrical conductivities of the composites
were dramatically increased compared with pure polyaniline and found to be 0.50 × 10 2 S/cm to 6.11 × 10 2 S/cm. The PA/EG composites showed a reversible electrochemical response up to 150th repeated cycles as revealed by the cyclic
voltametry study. 相似文献
4.
A simple and facile method was used to synthesize polyaniline (PANI) nanocomposites with sodium montmorillonite clay (Na +-MMT) using in situ intercalative oxidative polymerization. Aniline was admixed with Na +-MMT at various concentrations, keeping the aniline monomer in the reaction mixture constant. The intercalation of PANI into
the clay layers was confirmed by X-ray diffraction studies in conjugation with electron microscope techniques and FTIR spectra,
particularly by the narrowing of the Si–O stretching vibration band confirmed the interaction between PANI and the clay. The
employed route offers the possibility to improve the thermal properties with simultaneously controlled electrical conductivity.
Thermal studies show an improved thermal stability of the nanocomposites relative to the pure PANI. Depending on the loading
of the clay, the room temperature conductivity values of these nanocomposites varied between 2.0 × 10 −4 and 7.4 × 10 −4 S cm −1, with the maximum at 44 wt% PANI concentration. The decrease of electrical conductivity at high PANI concentration was ascribed
to the decrease of the structural ordering of PANI in the nanocomposite. 相似文献
5.
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. 相似文献
6.
Lightweight composite hollow spheres with conductive and magnetic properties were prepared by using Hollow Glass Spheres (HGS)
as substrate. The morphology, composition, conductive, and magnetic properties of the resultant products were characterized
by SEM, EDX, XRD, FTIR spectra, conductivity measurement, and vibrating-sample magnetometry. Polyaniline (PANI) were in situ
polymerized on HGS with increasing ratios of PANI to HGS, resulting in the enhanced conductivity of HGS/PANI composites from
1.3 × 10 −2 S/cm to 4.4 × 10 −2 S/cm. Lightweight glass/Fe 3O 4-PANI composite hollow spheres (HGS/Fe 3O 4-PANI) with conductivity of 5.4 × 10 −3 S/cm and magnetization of 9.25 emu/g were prepared by deposition of Fe 3O 4 nanoparticles onto HGS via electrostatic adsorption first, and then polymerization of aniline onto HGS/Fe 3O 4. The glass/PANI-Fe 3O 4 composite hollow spheres (HGS/PANI-Fe 3O 4) composed of Fe 3O 4 as the outmost layer and PANI as the inner layer were prepared for comparison. The conductivity and magnetization of HGS/PANI-Fe 3O 4 were 1.1 × 10 −4 S/cm and 2.61 emu/g, respectively. 相似文献
7.
Organic thermoelectric materials mainly conducting polymers are green materials that can convert heat energy into electrical energy and vice versa at room temperature. In the present work, we investigated the thermoelectric properties of polymer nanocomposite of polypyrrole (PPy) and polyaniline (PANI) (PPy/PANI) by varying the pyrrole: aniline monomer ratios (60:40, 50:50, and 40:60). The PPy/PANI composite is prepared by in-situ chemical polymerization of PPy on PANI dispersion. It has been observed that the combination of two conducting polymers has enhanced the electrical and thermal properties in the PPy/PANI composite due to the strong π–π stacking and H-bonding interaction between the conjugated structure of PPy and conjugated structure of PANI. The maximum electrical conductivity of 14.7 S m?1 was obtained for composite with high pyrrole content, whereas the maximum Seebeck coefficient of 29.5 μV K?1 was obtained for composite with high aniline content at 366 K. Consequently, the PPy/PANI composite with pyrrole to aniline monomer ratio of 60:40 exhibits the optimal electrical conductivity, Seebeck coefficient, and high power factor. As a result, the maximum power factor of 2.24 nWm?1 K?2 was obtained for the PPy/PANI composite at 60:40 pyrrole to aniline monomer ratio, which is 29 times and 65.8 times higher than PPy (0.077 nWm?1 K?2) and PANI (0.034 nWm?1 K?2), respectively. 相似文献
8.
Nanocomposites of polyfuran (PF) and polythiophene (PTP) with montmorillonite clay (MMT) were prepared and modified by loading
of polyaniline (PANI) and polypyrrole (PPY) moieties via polymerization of aniline (ANI) and pyrrole (PY) in aqueous dispersions
of PF-MMT and PTP-MMT nanocomposites. Formation of PANI and PPY and their subsequent incorporation in the PF-MMT and PTP-MMT
composites was confirmed by FTIR absorption studies. X-ray diffraction (XRD) patterns of PANI and PPY modified PF-MMT and
PTP-MMT composites showed that PF-MMT and PTP-MMT intercalates were still present in the modified composites. Scanning electron
microscopic analysis revealed distinctive morphological patterns of the various composite particles. The dc conductivity values
of PANI and PPY modified PF-MMT and PTP-MMT composites were in the order of 10 −2 S/cm in either system – a value much improved compared to the same for both of the unmodified PF-MMT (10 −7 S/cm) and PTP-MMT (10 −5 S/cm) nanocomposites respectively. 相似文献
9.
The aims of this work are to synthesize the HClO 4–graphite intercalation compound (GIC) by chemical method and analyze the effects of processing parameters on the exfoliated volume (EV) of HClO 4–GIC and in the meantime, characterize the structural characteristics of HClO 4–GIC and its exfoliated graphite by using X-ray diffraction. The experimental results show that the optimum condition for preparing the HClO 4–GIC with the maximum EV of 540 cm 3/g is that the intercalating reaction temperature, time, the thermally exfoliating temperature and the ratio between natural flake graphite, HClO 4 and HNO 3 are 373 K, 15 min, 1173 K and 1/4/0.15, respectively. The HClO 4–GIC synthesized through the optimum processing condition has EV of 360 cm 3/g at 473 K and the natural flake graphite also can be intercalated by HClO 4 at low temperature 258 K in the system. 相似文献
10.
Three-dimensional nanostructured polyaniline (PANI) and manganese oxide (MnO x ) composite porous microspheres were prepared by oxidizing aniline with KMnO 4 under interfacial chemical synthesis with 4-amino-thiophenol (4-ATP) as the structure-directing agent on the Au substrate. Surface morphology and chemical composition of PANI/MnO x microsphere were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, thermo gravimetric-differential thermal analysis, and Fourier transform infrared spectrum. The result displayed that concentration of KMnO 4 played a key role in forming the 3D nanostructured porous microspheres. To obtain the regular shapes and uniform sizes of the porous microspheres, the optimal concentration of oxidant was 0.15 mol L −1. The electrochemistry performances of PANI/MnO x microsphere were determined by cyclic voltammograms, electrochemical impedance spectroscopy, and galvanostatic charge–discharge. The specific capacitance of the 3D nanostructured PANI–MnO x porous microspheres exhibited a maximum value of 828 F g −1 at current density of 2 mA cm −2 over a potential range of 0.0–0.9 V versus SCE. It has improved 365 and 88 % comparing with that of PANI (178 F g −1) and MnO x (440 F g −1) obtained at the similar condition. The charge–discharge tests showed the PANI/MnO x microsphere possessed a good cycling stability. It maintained about 84.2 % of the initial capacitance after 1000 cycles at a current density of 2.0 mA cm −2. 相似文献
11.
Polyaniline polymer-coated MnTi-substituted strontium hexaferrite (Sr(MnTi)
x
Fe 12−2x
O 19/PANI, x = 1.0, 1.5, 2.0) composites were synthesized by the oxidative chemical polymerization of aniline in the presence of ammonium
peroxydisulfate. The structure and morphologies of the products were characterized by X-ray diffraction, FT-IR, TGA, SEM,
and TEM. In the magnetization for the Sr(MnTi)
x
Fe 12−2x
O 19/PANI composites, it was found that the saturation magnetization ( M
s) and coercivity ( H
c) decreased after polyaniline coating. The composite under an applied magnetic field exhibited hysteretic loops of ferromagnetic
behavior, such as high saturation magnetization ( M
s = 12.1–1.9 emu/g) and coercivity ( H
c = 0.919–0.084 kG). The composite specimens of core–shell Sr(MnTi)
x
Fe 12−2x
O 19/PANI and thermal plastic resin had a band-width microwave absorption due to the reflection losses from −15 to −35 dB at frequencies
between 18 and 40 GHz as observed by a high-frequency network analyzer. 相似文献
12.
Polyaniline (PANI) emeraldine salt form and PANI/silver composites have been synthesized by sonochemical and ionizing radiation
methods. These composite materials were obtained through sonication and γ irradiation of an aqueous solution of aniline and
silver nitrate, in room temperature, respectively. The mechanisms suggested to explain the formation of these products are
based on the fact that both methods produce hydroxyl radical •OH and hydrogen radical •H, where hydroxyl radical •OH acts as an oxidizing agent in the polymerization process of aniline monomer; and hydrogen radical •H, as a reducing agent for silver ions. Spectroscopic, X-ray, and SEM measures show that PANI and silver nano particles of
40 nm average diameter are produced with ultrasonic methods, whereas silver nano particles of 60 nm average, and fibrillar,
highly network morphology for PANI with 60 nm fibrillar diameter average are obtained using γ radiation). 相似文献
13.
This paper deals with the preparation, structural characterization, and physical performances of composites composed of biomass-based cellulose acetate propionate (CAP) and exfoliated graphene (EG). As a reinforcing nanofiller, EG is thus prepared by an oxidation/thermal expansion process of natural graphite flakes and it is characterized to consist of disordered graphene platelets. Structural features, thermal stability, mechanical modulus, and electrical resistivity of CAP/EG composites are investigated as a function of EG content. SEM and X-ray diffraction data demonstrate that graphene platelets of EG are well dispersed and exfoliated in the CAP matrix for the composites with up to ~1 wt.% EG, although they are partially aggregated in the composites with higher EG contents above ~3 wt.%. Thermo-oxidative stability of CAP/EG composites under active oxygen gas condition is improved substantially due to the gas barrier effect of graphene platelets of EG dispersed in the CAP matrix. Dynamic mechanical modulus of the composites is also enhanced significantly with increasing the EG content. This mechanical enhancement of CAP/EG composites is analyzed by adopting the Halpin–Tsai model. The electrical volume resistivity of CAP/EG composites prepared by melt-compounding is decreased dramatically from ~10 15 to ~10 6 Ω cm by forming the electrical conduction path at a certain EG content between 5 and 7 wt.%. 相似文献
14.
This paper deals with the preparation, structural characterization, and physical performances of composites composed of biomass-based cellulose acetate propionate (CAP) and exfoliated graphene (EG). As a reinforcing nanofiller, EG is thus prepared by an oxidation/thermal expansion process of natural graphite flakes and it is characterized to consist of disordered graphene platelets. Structural features, thermal stability, mechanical modulus, and electrical resistivity of CAP/EG composites are investigated as a function of EG content. SEM and X-ray diffraction data demonstrate that graphene platelets of EG are well dispersed and exfoliated in the CAP matrix for the composites with up to ∼1 wt.% EG, although they are partially aggregated in the composites with higher EG contents above ∼3 wt.%. Thermo-oxidative stability of CAP/EG composites under active oxygen gas condition is improved substantially due to the gas barrier effect of graphene platelets of EG dispersed in the CAP matrix. Dynamic mechanical modulus of the composites is also enhanced significantly with increasing the EG content. This mechanical enhancement of CAP/EG composites is analyzed by adopting the Halpin–Tsai model. The electrical volume resistivity of CAP/EG composites prepared by melt-compounding is decreased dramatically from ∼10 15 to ∼10 6 Ω cm by forming the electrical conduction path at a certain EG content between 5 and 7 wt.%. 相似文献
15.
Natural flake graphite (NFG) and perchloric acid (PA) were used as host material and intercalating agent, respectively, to synthesize graphite intercalation compound (GIC) through chemical method in the binary HClO 4-graphite system. The HClO 4-GIC was exfoliated above 200 °C to produce exfoliated graphite (EG). The exfoliating ability of HClO 4-GIC was characterized through its exfoliated volume (EV), i.e. the apparent volume of EG of per unit weight. The effect of some technological parameters on the EV was discussed in detail. The HClO 4-GIC prepared under the condition: the intercalating reaction temperature, time and the mass ratio of PA to NFG being 120 °C, 30 min and 5/1, respectively, has an outstandingly exfoliating ability at low temperature (200 °C) and its EV can attain 360 cm 3/g. In addition, the morphology characteristics of EG were characterized by scanning electron microscope. 相似文献
16.
以天然可膨胀石墨(GN)为原材料,采用酸及快速热处理制备了膨胀石墨(EG),再将膨胀石墨置于超声波中制得了纳米石墨微片(NanoG),最后采用原位聚合法制备了聚苯胺/纳米石墨微片(PANI/NanoG)导电复合物。扫描电镜(SEM)显示纳米石墨微片长径为0.8μm~20μm,厚度为30nm~90nm。聚苯胺均匀覆盖在纳米石墨微片表面;透射电镜(TEM)揭示了纳米石墨微片的片层分散在复合物中并形成了导电网络;电性能测试表明,当纳米石墨微片含量为0.5%(质量分数,下同)时,复合物电导率达到107.3S/cm,其渗滤阈值达到0.1%,纳米石墨微片独特的结构(宽度/厚度的高比值)及在聚苯胺中的分散造就了复合物良好的导电性能。 相似文献
18.
In this work, we present a new synthesis method for surfactant stabilized graphene (SSG) combined with polyaniline nanofiber (PANI-Nf) and apply the composite material as supercapacitor (SC) electrodes by screen-printing technique. Surfactant stabilized graphene polyaniline nanofiber composite (PANI-SSG) was synthesized by electrolytic exfoliation of graphite and subsequent interfacial polymerization. Firstly, graphite was electrolytically exfoliated in an electrolyte containing anionic surfactant. Next, ammonium peroxydisulfate initiator and hydrochloric acid were added to the graphene dispersion to form the aqueous phase for interfacial polymerization of polyaniline nanofiber. This dispersion was then added to the water-insoluble solvent phase containing aniline monomer. The polymerization only occurred at the interface of the two immiscible phases leading to polyaniline nanofiber decorated graphene structures. Characterizations by scanning electron microscopy, transmission electron microscopy, atomic force microscopy and Raman spectroscopy suggested nanocomposite formation with intermolecular π-π bonding of graphene with polyaniline nanofibers. Pastes of the materials were screen printed on stainless steel current collectors and tested for SC performance by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurements with 2 M H 2SO 4 electrolyte using a home-built two-electrode test-cell. CV results showed redox peaks of polyaniline with wide cyclic loop, indicating large pseudocapacitance of the nanocomposite. From GCD measurement, a high specific capacitance of 690 Fg −1 at 1 Ag −1 was achieved. Therefore, PANI-SSG nano-composite prepared by electrolytic exfoliation and interfacial polymerization is a promising candidate for SC applications. 相似文献
19.
In situ polymerization of aniline is carried out in the presence of zinc ferrite to synthesize polyaniline/ZnFe 2O 4 composites (PANI/ZnFe 2O 4) by chemical oxidation method. The composite has been synthesized with various compositions (10, 20, 30, 40 and 50 wt.%) of zinc ferrite in PANI. From the infrared spectroscopy (FTIR) studies on polyaniline/ZnFe 2O 4 composites, the peak at 1140 cm ?1 is considered to be measure of the degree of electron delocalization. The surface morphology of these composites is studied with scanning electron micrograph (SEM). The ac conductivity and dielectric properties are studied in the frequency range from 10 2 to 10 6 Hz. The results obtained for these composites are of scientific and technological interest. 相似文献
20.
Polyaniline (PANI) nanorods/Ce(OH) 3-Pr 2O 3/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, Pr 2O 3. In the experiment, sulphosalicylic acid was used as dopant, aniline was designated as oil phase and the aqueous solution comprising Ce 3+ and Pr 3+ 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. 相似文献
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