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1.
The strain-dependent electrical resistance characteristics of multi-walled carbon nanotube (MWCNT)/polymer composite films were investigated. In this research, polyethylene oxide (PEO) is used as the polymer matrix. Two representative volume fractions of MWCNT/PEO composite films were selected: 0.56?vol% (near the percolation threshold) and 1.44?vol% (away?from the percolation threshold) of MWCNT. An experimental setup which can measure electrical resistance and strain simultaneously and continuously has been developed. Unique and repeatable relationships in resistance versus strain were obtained for multiple specimens with different volume fractions of MWCNT. The overall pattern of electrical resistance change versus strain for the specimens tested consists of linear and nonlinear regions. A resistance change model to describe the combination of linear and nonlinear modes of electrical resistance change as a function of strain is suggested. The unique characteristics in electrical resistance change for different volume fractions imply that MWCNT/PEO composite films can be used as tunable strain sensors and for application into embedded sensor systems in structures. 相似文献
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Polypyrrole/multiwalled carbon nanotube (MWNT) composite films were electrochemically deposited in the presence of an ionic
surfactant, sodium dodecyl sulfate (SDS), acting as both supporting electrolyte and dispersant. The effects of the surfactant
and the MWNT concentrations on the structure of the resulting composite films were investigated. The electrochemical behavior
of the resulting polypyrrole/MWNT composite film was investigated as well by cyclic voltammogram. The effect of the additional
alternating electric field applied during the constant direct potential electrochemical deposition on the morphology and electrochemical
behavior of the resulting composite film was also investigated in this study. 相似文献
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A water/oil microemulsion system having been successfully used for synthesizing polyaniline(PANi) nanoparticles, was employed for preparing PANi/multi-walled carbon nanotube (MWCNT) nanocomposites via in situ chemical oxidative polymerization. The structures and the electrical property of PANi/MWCNT nanocomposites were also studied. The studies showed that PANi could coat MWCNTs to form nanocables with core-shell structure, and the backbone structure of PANi was not damaged by the introduction of MWCNTs. The conductivities of PANi/MWCNT nanocomposites were higher than that of PANi. Moreover, a model was supposed to be used for describing a PANi/MWCNT nanocable formation by in situ microemulsion polymerization. 相似文献
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Porous polyaniline (PANI)-coated multi-walled carbon nanotube (MWNT) core/shell nanohybrids were fabricated through in situ polymerization and subsequently assembled into macroscopic composites. N(2) adsorption/desorption analysis indicated that the volume of nanopores increased significantly, which could make a significant contribution to phonon scattering. Thermal annealing was also carried out to improve the Seebeck coefficient of the as-produced nanocomposites. The optimal sample showed electrical conductivity of 14.1?S?cm(-1), a Seebeck coefficient of 79.8?μV K(-1) and thermal conductivity of 0.27?W?mK(-1), resulting in a highest figure of merit (ZT) of 0.01 at a very low loading of MWNTs (<1?wt%). These results will provide a potential direction to enhance thermoelectric performance of organic materials and also facilitate the application of organic materials in thermal energy harvesting or cooling. 相似文献
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Kim YJ Shin MK Kim SJ Kim SK Lee H Park JS Kim SI 《Journal of nanoscience and nanotechnology》2007,7(11):4185-4189
We have fabricated for the first time one-dimensional multiwalled carbon nanotube (MWNT) nanocomposite fibers with improved electrical properties using electrospinning. Polyaniline (PANi) and poly(ethylene oxide) (PEO) were used as a conducting and a nonconducting matrix, respectively, for hybrid nanofibers including MWNTs. The hybrid nanofibers fabricated by electrospinning had a length of several centimeters and a diameter ranging from approximately 100 nm to approximately 1 microm. Transmission electron microscopic analysis confirmed that the MWNTs were successfully oriented along the fiber axis without any severe aggregation during electrospinning. The hybrid nanofibers showed an enhanced electrical conductance with increasing MWNT content up to 0.5 wt%, and compared to PANi/PEO fibers, they also showed a stable linear ohmic behavior. These hybrid conducting nanofibers can be applied to chemical and biosensors that require a high sensitivity. 相似文献
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Composites of carbon nanotubes with attached carboxylic groups (c-MWCNTs) and water-soluble externally doped sulfonated polyaniline (ED-SPANI) were prepared by solution mixing of c-MWCNT and ED-SPANI aqueous colloids. Fourier-transform infrared spectroscopy, Raman spectroscopy, ultraviolet–visible (UV–Vis) absorption spectroscopy, field-emission scanning and high-resolution transmission electron microscopy were used to characterize their structure and morphology. Raman and UV–Vis spectra revealed the presence of electrostatic interaction between the C–N+ species of the ED-SPANI and the COO− species of the c-MWCNTs. The addition of c-MWCNT to ED-SPANI can improve its thermal stability. The conductivity of 3 wt.% ED-SPANI/c-MWCNT composites at room temperature is sixteen times higher than that of ED-SPANI. These results demonstrate that the addition of a small number of c-MWCNTs to an ED-SPANI matrix can form a conducting network in well dispersed composites, thus increasing their electrical conductivity. 相似文献
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《Journal of Experimental Nanoscience》2013,8(7-8):947-956
The anodic oxidation of sulphadiazine (SD) was investigated at a glassy carbon electrode modified by multi-walled carbon nanotube (MWCNT–GCE), using cyclic voltammetry and chronoamperometry. The results indicate that MWCNT-modified GCEs show an efficient and selective electrocatalytic activity towards the anodic oxidation of SD among biologically important compounds in buffered solutions at pH?=?7. It was found that oxidation of SD at the surface of MWCNT–GCE occurs at a potential less positive than that of unmodified GCE (about 100?mV). The diffusion coefficient of SD was also estimated using chronoamperometry. The kinetic parameters such as the electron transfer coefficient between SD and modified electrode, α, and the charge transfer rate constant, ks , for oxidation of SD at the MWCNT–GCE surface were determined according to the Laviron procedure. The dissociation constants of oxidised and reduced acid–base species of SD can be obtained from the E 1/2 versus pH curves. The linear dependence of the peak current on the concentration was observed in the range 10–2000?µmol?L?1 with a detection limit of 7.1?µmol?L?1. The method was also applied to determinate the SD in human blood plasma and urine samples. 相似文献
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Michael D. ClarkRamanan Krishnamoorti 《Thin solid films》2012,520(13):4332-4338
Thin films of multi-walled carbon nanotubes created by standard drop and dry methodology are reported here to give water contact angles of ~ 138° accessing an intermediate region between smooth, apolar materials and superhydrophobic surfaces. Their near-superhydrophobic nature is attributed to hierarchical nanoscale roughness leading to the formation of Cassie-Baxter interfaces. While complete quantitative determination of surface energy parameters was prevented due to the porous nature of the films, the dispersive component of nanotube surface energy was found to be in the range of 39.1-47.8 mJ/m2. 相似文献
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《Journal of Experimental Nanoscience》2013,8(1):355-362
ABSTRACTPolyaniline (PAN) composites filled with nanotube were prepared by twin-screw extruder in order to study the influence of PE reinforcing effect on the mechanical behaviour of the nanotube/polyaniline (PAN) composites. The mechanical property tests of the composites with and without PE were performed. The tensile and flexural strength of nanotube/polyaniline (PAN) composites with polyethylene (PE) was improved. In conclusion, the addition of PE favoured the improvement of the higher interface strength and so had good effect on improving the tensile and flexural properties of the composites. The dielectric strength was slightly increased with the PE content increasing and then decreased gradually. The hybrid film with 2 wt.% of PE shows the dielectric strength of 199 MV/m, which is about 6% higher than that of nanotube/polyaniline (PAN) film (188 MV/m). 相似文献
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将多壁碳纳米管(MWCNTs)水悬浮液、N-甲基吗啉-N-氧化物(NMMO)溶液及纤维素共混得到纺丝液,通过干湿法制备了Lyocell/MWCNT复合纤维。采用X-衍射仪(WAXD)、扫描电镜(SEM)、透射电镜(TEM)、强度仪等分析了所得纤维的结构和性能。WAXD图谱显示复合纤维仍然具有纤维素II晶型的结构,同时还保留了MWCNTs的特征衍射峰;二维X衍射结果表明:MWCNTs质量分数为5%的复合纤维中,MWCNTs与纤维轴的取向角为±15.2°,说明复合纤维中MWCNTs基本沿着纤维轴取向。SEM结果显示复合纤维中MWCNTs在Lyocell基体中分布均匀。对纤维的力学性能分析进一步表明:添加适量的MWCNTs可使复合纤维的力学性能提高,MWCNTs质量分数为1%的复合纤维的初始模量和强度分别比Lyocell纤维增加49.4%和15.7%。 相似文献
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In this paper, multi-walled carbon nanotube (MWCNT) ink was selectively patterned by inkjet printing on substrates to form conductive traces and electrodes for interconnection application. MWCNT was firstly functionalized using concentrated acid and dispersed in deionized water to form a colloidal solution. Various concentrations of MWCNT were formulated to test the stability of the solution. The printability of the MWCNT ink was examined against printing temperature, ink concentration and ink droplet pitch. Rheological properties of the ink were determined by rheometer and sessile drop method. The electrical conductivity of the MWCNT pattern was measured against multiple printing of MWCNT on the same pattern (up to 10 layers). While single layer printing pattern exhibited highest resistance, the CNT entangled together and formed a random network with more printed layers has higher conductivity. The electrical properties of the printed film was compared to a composite ink of CNT and conducting polymer (CNT ink was mixed with conductive polymer solution, Poly(3,4-ethylenedioxythiophene)-Poly(styrenesulfonate) (PEDOT:PSS)). Scanning electron microscopy (SEM) was used to observe the surface structure and atomic force microscopy (AFM) was used to study the morphology of the printed film under different conditions. 相似文献
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Zonghua Wang Jianfei Xia Yanzhi Xia Caiyu Lu Guoyu Shi Feifei Zhang Fuqiang Zhu Yanhui Li Linhua Xia Jie Tang 《Materials science & engineering. C, Materials for biological applications》2013,33(7):3931-3934
A zirconia/multi-walled carbon nanotube (ZrO2/MWCNT) mesoporous composite was fabricated via a simple method using a hydrothermal process with the aid of the cationic surfactant cetyltrimethylammonium bromide (CTAB). Transmission electron microscopy (TEM), N2 adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the as-made samples. The cubic ZrO2 nanocrystallites were observed to overlay the surface of MWCNTs, which resulted in the formation of a novel mesoporous–nanotube composite. On the basis of a TEM analysis of the products from controlled experiment, the role of the acid-treated MWCNTs and CTAB was proposed to explain the formation of the mesoporous–nanotube structure. The as-made composite possessed novel properties, such as a high surface area (312 m2 · g? 1) and a bimodal mesoporous structure (3.18 nm and 12.4 nm). It was concluded that this composite has important application value due to its one-dimensional hollow structure, excellent electric conductivity and large surface area. 相似文献
16.
《材料与设计》2015
The aim of this work was to investigate the effects of relative humidity on the formation of titania layers on the surface of multi-walled carbon nanotubes under regulated conditions in a sealed system. Reactive precursor compounds such as titanium (IV) oxychloride hydrochloric acid and titanium (IV) bromide were used as precursor to cover the surface of multi-walled carbon nanotubes (MWCNTs) under solvent conditions. The mixtures of MWCNTs and titania compounds were not stirred or sonicated. The effect of relative humidity was influenced using the mixture of sulphuric acid and water in desiccators. As-prepared titan-dioxide (TiO2) layers were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TG), X-ray diffraction (XRD) and Raman spectroscopy. Our results revealed that TiO2 layers with different thicknesses can be obtained using this simple sealed system. These TiO2 covered multi-walled carbon nanotube films can be ideal candidates for different kinds of applications (e.g. sensors, virus filtration or catalysts). 相似文献
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Novel polystyrene microsphere (PSMS)-based PSMS/Si and polystyrene/silica nanoparticle/multi-walled carbon nanotube (PS/Si/MWCNT) nanocomposite has been prepared using in situ sol-gel and chemical amalgamation methods. Aniline monomer was introduced by in situ route to form PSMS/PANI, PSMS/PANI/Si and PSMS/PANI/Si/MWCNT nanocomposite. FESEM of nanocomposite indicated core-shell spherical and tubular morphology. Glass transition temperature (Tg) and maximum decomposition temperature (Tmax) of PSMS/PANI/Si/MWCNT nanocomposite were found as 295°C and 524°C, respectively, which were higher than the PSMS/PANI (Tg = 245°C; Tmax = 387°C) and PSMS/PANI/Si (Tg = 257°C; Tmax = 388°C) nanocomposite. For nanocomposite dispersion, tetrahydrofuran was studied as fine solvent. XRD depicted amorphous nature of PSMS/Si and PSMS/PANI/Si; however MWCNT reduced amorphous character of PSMS/PANI/Si/MWCNT. Electromagnetic interference (EMI) shielding effectiveness improved from 0.1 dB (PSMS) to 12.3 dB (PSMS/PANI/Si) to 24.5 dB (PSMS/PANI/Si/MWCNT). The increase in EMI shielding effectiveness was also observed with variation in log of conductivity from ?14 mho m?1 (PSMA) to 1.17 mho m?1 (PSMS/PANI/Si/MWCNT). 相似文献
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Composites of polyaniline (PANI) and multi-wall carbon nanotube (MWNT) were synthesized by in situ polymerization with different MWNT content. The composites were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The SEM photos indicated that a mass of MWNT was enchased into PANI matrix when the content of MWNT was low. With the MWNT content increases, the surface of MWNT was covered with PANI and formed the core-shell structure. From the FT-IR spectroscopy of the composites, it can be confirmed that there was interaction between PANI and multi-wall carbon nanotube. The composites had better thermal stability than pure PANI. Infrared emission property of the composites was analyzed by an IR-II infrared emissivity instrument and an infrared camera. It was found that infrared emission of the composites was lower than pure PANI in all wavelength range and infrared emissivity value was related to the content of MWNT in the composites. 相似文献
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Precious metal nanoparticles were prepared on carbon nanotube (CNT) by sequential and simultaneous deposition methods for the electrocatalytic study of methanol oxidation. All electrochemical measurements were carried out in a three-electrode cell. A Platinum wire and Ag/AgCl were used as auxiliary and reference electrodes, respectively. Suspension of the CNT and Nafion were mixed and dropped on glassy carbon as a working electrode. Cyclic voltammograms in H2SO4 electrolyte solution are attributable to hydrogen adsorption and hydrogen desorption resulting in promising electrochemical performance of the prepared precious metal nanoparticles. Cyclic voltamograms of methanol electrooxidation studied in 2 M CH3OH in 1 M H2SO4 show a distinguishing shape with a prominent oxidation wave in the anodic scan contributed to methanol oxidation while the cathodic scan is associated with the accumulation of carbonaceous species. 相似文献