22 research outputs found

    Surface characterization of new biomaterials

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    Link to publisher's homepage at https://iopscience.iop.org/This paper presents the characterization of new alloys CoCrMoSi6, CoCrMoSi7, CoCrMoSi10, in terms of hardness determinations, fractographic analysis and surface analysis. The original version of the alloy was obtained by casting process in a vacuum arc furnace. Experimental results obtained from this study confirms that by increasing content of silicon, the mechanical properties are superior and the positive results obtained at surface studies favoring the formation of compounds, that lead to the reduction of alloying grade for α solid solution and the plasticity of the alloys

    Synthesis, Characterization, and Evaluation of [Ir(ppy)<sub>2</sub>(vpy)Cl] as a Polymer-Bound Oxygen Sensor

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    This study reports new luminescent oxygen sensors in which the luminophore is covalently bound to the polymer matrix and compares their behavior to related sensors in which the luminophore is dispersed within the matrix. The cyclometalated iridium complex [Ir(ppy)2(vpy)Cl], 1, has been synthesized and characterized spectroscopically (absorption and emission) and by 1-D and 2-D 1H NMR, elemental analysis, and X-ray crystallography. Complex 1 was attached via hydrosilation to hydride-terminated poly(dimethylsiloxane) (PDMS), yielding material 2. Successful luminophore attachment was determined spectroscopically from the emission properties, and through the altered physical behavior of 2 compared to a dispersion of 1 in PDMS. Hydrosilation of 1 with dimethylphenylsilane yielded [Ir(ppy)2(DMPSEpy)Cl], 3, which was fully characterized and used to probe the effect of hydrosilation on the spectroscopic properties of the luminophore. Evaluation of 2 as a luminescent oxygen sensor revealed significantly improved sensitivity over dispersions of 1 in PDMS. Material 2 was also blended with polystyrene (PS) to improve the physical properties of the sensor films. The blend sensors exhibited increased sensitivity relative to films of 2 alone and maintained short response times to rapid changes in air pressure. In contrast, 1 partitioned into the PS phase when dispersed in a PDMS/PS blend, resulting in longer sensor response times

    Synthesis, Characterization, and Evaluation of [Ir(ppy)<sub>2</sub>(vpy)Cl] as a Polymer-Bound Oxygen Sensor

    No full text
    This study reports new luminescent oxygen sensors in which the luminophore is covalently bound to the polymer matrix and compares their behavior to related sensors in which the luminophore is dispersed within the matrix. The cyclometalated iridium complex [Ir(ppy)2(vpy)Cl], 1, has been synthesized and characterized spectroscopically (absorption and emission) and by 1-D and 2-D 1H NMR, elemental analysis, and X-ray crystallography. Complex 1 was attached via hydrosilation to hydride-terminated poly(dimethylsiloxane) (PDMS), yielding material 2. Successful luminophore attachment was determined spectroscopically from the emission properties, and through the altered physical behavior of 2 compared to a dispersion of 1 in PDMS. Hydrosilation of 1 with dimethylphenylsilane yielded [Ir(ppy)2(DMPSEpy)Cl], 3, which was fully characterized and used to probe the effect of hydrosilation on the spectroscopic properties of the luminophore. Evaluation of 2 as a luminescent oxygen sensor revealed significantly improved sensitivity over dispersions of 1 in PDMS. Material 2 was also blended with polystyrene (PS) to improve the physical properties of the sensor films. The blend sensors exhibited increased sensitivity relative to films of 2 alone and maintained short response times to rapid changes in air pressure. In contrast, 1 partitioned into the PS phase when dispersed in a PDMS/PS blend, resulting in longer sensor response times
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