The linear conjugated polymer of polyfluorene/ poly(p-phenylenevinylenes) (PFO/PPV) was synthesized and selected as the matrix film. The incorporation of a small fraction of inorganic mesoporous silicas into the polym...
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The linear conjugated polymer of polyfluorene/ poly(p-phenylenevinylenes) (PFO/PPV) was synthesized and selected as the matrix film. The incorporation of a small fraction of inorganic mesoporous silicas into the polymer matrix resulted in a significant increase in overall detection efficiency of nitroaromatics. The structure of the obtained mixed films was characterized by 'H-NMR, IR, and XRD. The optical and fluorescence properties of the mixed films were demonstrated by ultraviolet and visible spectro-scopy (UV-Vis) and photoluminescence (PL) spectra in ethanol/water solution. Compared with the pure conjugated polymer film, the mixed films had high fluorescence quenching sensitivity toward nitroaromatic compounds, especially 2,4,6-trinitrophenol (TNP), in the aqueous phase. The fluorescent emission quenching is quantitative and can be analyzed on the basis of the Stern-Volmer model relation with the quenching process. The results revealed that such mixed matrix films of conjugated polymer/mesoporous silicas can be a promising strategy of designing chemosensory materials for detecting nitroaromatic compounds.
Using a hybrid computational approach, we simulate the behavior of nanoparticle-filled microcapsules that are propelled by an imposed shear to move over a substrate, which encompasses a microscopic crack. When the mic...
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Research and development in textiles have gone beyond the conventional applications as clothing and furnishing materials;for example, the convergence of textiles, nanotechnologies, and energy science opens up the oppo...
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Research and development in textiles have gone beyond the conventional applications as clothing and furnishing materials;for example, the convergence of textiles, nanotechnologies, and energy science opens up the opportunity to take on one of the major challenges in the 21st century-energy. This presentation addresses the development of high-energy lithium-ion batteries using electrospun nanofibers.
The thermal conductivity of wurtzite and zinc blende indium arsenide nanowires was measured using a microfabricated device, with the crystal structure of each sample controlled during growth and determined by transmis...
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The thermal conductivity of wurtzite and zinc blende indium arsenide nanowires was measured using a microfabricated device, with the crystal structure of each sample controlled during growth and determined by transmission electron microscopy. Nanowires of both phases showed a reduction of the thermal conductivity by a factor of 2 or more compared to values reported for zinc blende indium arsenide bulk crystals within the measured temperature range. Theoretical models were developed to analyze the measurement results and determine the effect of phase on phonon transport. Branch-specific phonon dispersion data within the discretized first Brillouin zone were calculated from first principles and used in numerical models of volumetric heat capacity and thermal conductivity. The combined results of the experimental and theoretical studies suggest that wurtzite indium arsenide possesses similar volumetric heat capacity, weighted average group velocity, weighted average phonon-phonon scattering mean free path, and anharmonic scattering-limited thermal conductivity as the zinc blende phase. Hence, we attribute the differing thermal conductivity values observed in the indium arsenide nanowires of different phases to differences in the surface scattering mean free paths between the nanowire samples.
New polyfluorene copolymers containing phenothiazine derivatives have been designed, synthesized, and characterized. Synthesized copolymers, PFPCVBs and PFPTRs, are shown that their CIE coordinate values are very clos...
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The effective use of recycled supernatant that contains temperature-responsive fl occulant is demonstrated for solid-liquid separations. The recyclability of poly(N-isopropylacrylamide) (PNIPAM) of several different m...
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ISBN:
(纸本)9781617820519
The effective use of recycled supernatant that contains temperature-responsive fl occulant is demonstrated for solid-liquid separations. The recyclability of poly(N-isopropylacrylamide) (PNIPAM) of several different molecular weights and a 15 per cent negatively charged derivative are compared. Batch settling tests of a-alumina suspensions are fi rst conducted at 50°C, with a subsequent 25°C period, after which the supernatant is harvested and used to fl occulate subsequent suspensions. Using this procedure consecutive separations are obtained with the repeated recycling of uncharged PNIPAM containing supernatant. Batch settling tests indicate that hindered settling rates increase with molecular weight of PNIPAM. Adsorption studies indicate that strong adsorption of PNIPAM onto alumina occurs with PNIPAM at 50°C and that signifi cant desorption occurs after cooling at 25°C. However, the extent of desorption decreases with molecular weight resulting in low amounts of PNIPAM for recycling and poor settling behaviour when high molecular weight PNIPAM is recycled. Little recyclability was evident using the negatively charged PNIPAM. On the basis of these fi ndings a recycling-thickener apparatus that uses low molecular weight uncharged PNIPAM is proposed.
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