20 resultados para polyaniline nanotubes


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We demonstrated an Erbium-doped picosecond fiber laser mode locked by carbon nanotube in N-methyl-2-pryrrolidone solvent in an in-fiber micro-channel. © 2011 Optical Society of America.

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We explored the potential of a carbon nanotube (CNT) coating working in conjunction with a recently developed localized surface plasmon (LSP) device (based upon a nanostructured thin film consisting of of nano-wires of platinum) with ultra-high sensitivity to changes in the surrounding index. The uncoated LSP sensor’s transmission resonances exhibited a refractive index sensitivity of Δλ/Δn ~ -6200nm/RIU and ΔΙ/Δn ~5900dB/RIU, which is the highest reported spectral sensitivity of a fiber optic sensor to bulk index changes within the gas regime. The complete device provides the first demonstration of the chemically specific gas sensing capabilities of CNTs utilizing their optical characteristics. This is proven by investigating the spectral response of the sensor before and after the adhesion of CNTs to alkane gases along with carbon dioxide. The device shows a distinctive spectral response in the presence of gaseous CO2 over and above what is expected from general changes in the bulk refractive index. This fiber device yielded a limit of detection of 150ppm for CO2 at a pressure of one atmosphere. Additionally the adhered CNTs actually reduce sensitivity of the device to changes in bulk refractive index of the surrounding medium. The polarization properties of the LSP sensor resonances are also investigated and it is shown that there is a reduction in the overall azimuthal polarization after the CNTs are applied. These optical devices offer a way of exploiting optically the chemical selectivity of carbon nanotubes, thus providing the potential for real-world applications in gas sensing in many inflammable and explosive environments. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

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Carbon nanotubes (CNTs) possess both remarkable optical properties and high potential for integration in various photonic devices. We overview, here, recent progress in CNT applications in fibre optics putting particular emphasis on fibre lasers. We discuss fabrication and characterisation of different CNTs, development of CNT-based saturable absorbers (CNT-SA), their integration and operation in fibre laser cavities putting emphasis on state-of-the-art fibre lasers, mode locked using CNT-SA. We discuss new design concepts of high-performance ultrafast operation fibre lasers covering ytterbium (Yb), bismuth (Bi), erbium (Er), thulium (Tm) and holmium (Ho)-doped fibre lasers.

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Self-organization of organic molecules with carbon nanomaterials leads to formation of functionalized molecular nano-complexes with advanced features. We present a study of physical and chemical properties of carbon nanotube-surfactant-indocarbocyanine dye (astraphloxin) in water focusing on aggregation of the dye and resonant energy transfer from the dye to the nanotubes. Self-assembly of astraphloxin is evidenced in absorbance and photoluminescence depending dramatically on the concentrations of both the dye and surfactant in the mixtures. We observed an appearance of new photoluminescence peaks in visible range from the dye aggregates. The aggregates characterized with red shifted photoluminescence peaks at 595, 635 and 675 nm are formed mainly due to the presence of surfactant at the premicellar concentration. The energy transfer from the dye to the nanotubes amplifying near-infrared photoluminescence from the nanotubes is not affected by the aggregation of astraphloxin molecules providing important knowledge for further development of advanced molecular nano-complexes. The aggregation with the turned-on peaks and the energy transfer with amplified photoluminescence create powerful tools of visualization and/or detection of the nanotubes in visible and near-infrared spectral range, respectively, boosting its possible applications in sensors, energy generation/storage, and healthcare.

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The unique properties of carbon nanotubes have made them the material of choice for many current and future industrial applications. As a consequence of the increasing development of nanotechnology, carbon nanotubes show potential threat to health and environment. Therefore, development of efficient method for detection of carbon nanotubes is required. In this work, we have studied the interaction of indopentamethinedioxaborine dye (DOB-719) and single-walled carbon nanotubes (SWNTs) using absorption and photoluminescence (PL) spectroscopy. In the mixture of the dye and the SWNTs we have revealed new optical features in the spectral range of the intrinsic excitation of the dye due to resonance energy transfer from DOB-719 to SWNTs. Specifically, we have observed an emergence of new PL peaks at the excitation wavelength of 735 nm and a redshift of the intrinsic PL peaks of SWNT emission (up to 40 nm) in the near-infrared range. The possible mechanism of the interaction between DOB-719 and SWNTs has been proposed. Thus, it can be concluded that DOB-719 dye has promising applications for designing efficient and tailorable optical probes for the detection of SWNTs.