A novel approach for the fabrication of transistors and circuits based on individual single-crystalline ZnO nanowires synthesized by a low-temperature hydrothermal method is reported. The gate ...dielectric of these transistors is a self-assembled monolayer that has a thickness of 2 nm and efficiently isolates the ZnO nanowire from the top-gate electrodes. Inverters fabricated on a single ZnO nanowire operate with frequencies up to 1 MHz. Compared with metal–semiconductor field-effect transistors, in which the isolation of the gate electrode from the carrier channel relies solely on the depletion layer in the semiconductor, the self-assembled monolayer dielectric leads to a reduction of the gate current by more than 3 orders of magnitude.
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The preparation of water repellent textiles by coating with different modified silica sols has been investigated. For this, pure and with 3-glycidoxypropyl triethoxysilane co-condensed silica sols ...were modified by three types of additives: alkyltrialkoxysilanes, polysiloxane derivatives and a fluorine containing silane. Hydrophobic properties of the coated fabrics of polyamide and of polyester mixed with cotton were determined using contact angle measurements. The hydrophobicity increases with increasing concentration of the alkylsilane additive in the silica sol and the length of the alkyl chain but with high additive concentrations plateau values in hydrophobicity were reached. Analogously textile coatings with high hydrophobicity were gained using hydrophobic polysiloxane or fluorine containing silicon compounds. The comparison of the different variants reveals that high wash-out stabilities were reached only by silica sols containing fluorine compoundsand hexadecylsilane additives. Therefore long-chain alkyltrialkoxysilane compounds could be used as substitutes for fluorine compounds for the surface modification of textiles in some practical applications.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Photoinduced linkage isomers (PLIs) of NO and NO 2 − are selectively generated by an appropriate choice of irradiation wavelength at low temperature within the same molecular complex Rh(NO)(NO 2 ) 2 ...(Bu t 2 PH) 2 . The structures of the PLIs are characterised by photocrystallography and the corresponding vibrational changes by infrared spectroscopy. Using red light about 37% of the κON isonitrosyl PLI can be produced while irradiation with blue light produces about 80% of the (O,O′) chelating NO 2 − isomer. Upon heating the NO 2 − PLI undergoes several structural transformations, which are characterised by infrared spectroscopy.
The ultraviolet (UV) protection of organic and biological materials against photodestruction is of high practical interest. Since protective coatings containing individual organic or inorganic UV ...absorbers contain absorption bands in different wavelengths regions below 400 nm, a combination of both types of absorbers can improve the UV protection functionality. Nowadays, the recent sol–gel technique enables the preparation of coatings from inorganic UV absorbers like TiO
2 combined with embedded organic UV absorbers. The absorption behavior of these hybrid coatings on glass was investigated as function of layer thickness and concentration for two different organic UV absorbers (based on benztriazol and phenylacrylate). The optimization of the coating composition is supported by model calculations of the transmission spectra and allows the preparation of coatings with nearly perfect light absorption at
λ
<
400 nm.
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The synthesis of bis-cyclometalated complexes M(ptpy)2(S2COCH3) (M=Rh, 1; M=Ir, 2; ptpy=2-(p-tolyl)pyridinato) from {M(μ-Cl)(ptpy)2}2, carbon disulfide, and sodium methanolate as the base is ...described. The molecular structures of the new compounds were confirmed by single-crystal X-ray diffraction studies. Display omitted
► Bis-cyclometalated complexes M(ptpy)2(S2COCH3) (M=Rh, Ir) were prepared from {M(μ-Cl)(ptpy)2}2, CS2 and NaOCH3. ► X-ray structure determination shows trans-N,N-cis-C,C-cis-S,S configuration for both compounds. ► The Rh compound is a weak red emitter.
The synthesis of the bis-cyclometalated complexes M(ptpy)2(S2COCH3) (M=Rh, 1; M=Ir, 2; ptpy=2-(p-tolyl)pyridinato) from {M(μ-Cl)(ptpy)2}2, carbon disulfide and sodium methanolate as the base are described. Compound 1 and 2, respectively, were crystallized from dichloromethane/methanol and the molecular structures of both complexes were confirmed by single-crystal X-ray diffraction studies (both monoclinic, P21/c). The emission spectrum of 1 exhibited the new compound as a red-emitting complex.
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Hydrophobic silica sol coatings on textiles were investigated with respect to the influence of the solvents and the concentration of the sol. For this purpose, two silica sols, prepared with the ...hydrophobic additives octyltriethoxysilane and perfluoroctyltriethoxysilane were diluted by different solvents: water, ethanol and aceton.In case of using pure water for dilution, the hydrophobicity of coated textiles decreases drastically with increasing dilution of the applied sol. For coatings on polyester fabrics or mixed fabrics made from polyester and cotton, the use of the organic solvents ethanol or aceton leads to significant hydrophobicity even in case of strong dilution down to a sol concentration < 1%. The hydrophobic effect of coated polyamide textile is less. The reason for different hydrophobicity of coated textiles resulting from the use of water instead of organic solvents is explained by different surface morphologies of the coatings deposited on the textile fibres, as observed by REM. In case of using organic solvents the coatings contain a more flat morphology which covers the fibres completely. In contrast, sols with higher water content lead to less adhesive coatings with crack formation.The use of a combination of water with less inflammable organic solvents such as di(propylene glycol) n-propyl ether (DowanolTMDPnP) in hydrophobic silica sols yields textile coatings with good hydrophobicity, even in case of low sol concentration. For practical application of textile coatings, especially silica sols with high water content are of interest, due to less risk of inflammation and lower ecological impact. Therefore, the use of water diluted hydrophobic silica sols with small amounts of DPnP offers a chance for textile refinement by the sol–gel technique.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Ag and Ag/SiO
2
sols containing nanocrystalline silver particles can be advantageously prepared by solvothermal methods using an autoclave with conventional thermal or microwave heating. In this ...process, the reduction of silver salts can be realized with alcohols like ethanol in the presence of polyvinylpyrrolidone at temperatures of more than 120 °C. Furthermore a combination of silver salt reduction with hydrolysis of alkoxysilanes during the solvothermal process can yield Ag/SiO
2
composite sols. Particle size and crystallinity of as-prepared particles are analyzed by means of X-ray diffraction and high-resolution transmission electron microscopy. Nanosized silver particles gained by this process exhibit antimicrobial properties that are investigated in detail after application on textile fabrics.
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Zusammenfassung
Aufgrund verbesserter Prognosen können viele Patientinnen und Patienten mit einer Krebsdiagnose heute wieder in das Berufsleben zurückkehren. Das vorliegende systematische Review ...untersucht geschlechtsspezifische Unterschiede der beruflichen Folgen einer Krebserkrankung. Dafür wurde eine systematische Datenbankrecherche der zwischen 01/2001 und 07/2011 publizierten Literatur zu beruflichen Folgen von Krebs durchgeführt. 44 Originalarbeiten entsprachen den Einschlusskriterien (erwachsene Krebspatienten, Fokus auf arbeitsbezogene Outcomes, geschlechtsbezogen berichtete Ergebnisse). Die Ergebnisse dieser Studien weisen darauf hin, dass Patientinnen im Vergleich zu Patienten eher Leistungseinschränkungen bei der Berufsausübung erleben, ihre Arbeitszeit häufiger verkürzen und tendenziell mehr Einkommenseinbußen verzeichnen. Ein supportives Arbeitsumfeld scheint insbesondere für Patientinnen einen wichtigen Einflussfaktor auf die erfolgreiche und dauerhafte Reintegration ins Arbeitsleben darzustellen. Es bedarf einer systematischeren Erforschung und stringenterer geschlechtsbezogener Analysen, um Gender-Aspekte arbeitsbezogener Outcomes nach einer Krebsdiagnose zu verstehen. Eine umfassendere Wissensbasis kann Hinweise geben, wie die Wiedereingliederung in den Beruf mit Blick auf geschlechtsspezifische Besonderheiten erfolgen kann.
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Embedding of the well-known coronary therapeuticum nifedipine into a modified silica matrix by the sol-gel technique allows its releasing behavior to be controlled to a high degree. The liberation ...rate is proportional to temperature and is increased by the addition of penetration agents such as sorbitol, but is inversely proportional to particle size and is decreased by modification of the silica matrix with methyl-triethoxysilane or polyethylene-glycol. It is presumed that the drug is dispersed in the gel matrix and that diffusion occurs through solvent-filled capillary channels. The liberation rate is governed by the relationship between the rates of dissolution and diffusion.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
10.
Antimicrobial sol-gel coatings MAHLTIG, B; FIEDLER, D; BÖTTCHER, H
Journal of sol-gel science and technology,
12/2004, Volume:
32, Issue:
1-3
Conference Proceeding, Journal Article
Peer reviewed
The preparation and the releasing behavior of modified silica coatings, containing embedded biocides on textiles, were compared and assessed with regard to application parameters like antimicrobial ...efficacy, wash-out and long-term behavior. For this, silica layers with embedded silver, silver salts and biocidal quaternary ammonium salts (cetyltrimethylammoniumbromid and octenidine) were investigated. Both the growth of fungi and bacteria can be inhibited by coatings with embedded biocides. Especially by using octenidine, an excellent long-term inhibition of fungi growth can be reached.
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