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81.
Hurst SJ Payne EK Qin L Mirkin CA 《Angewandte Chemie (International ed. in English)》2006,45(17):2672-2692
In the science and engineering communities, the nanoscience revolution is intensifying. As many types of nanomaterials are becoming more reliably synthesized, they are being used for novel applications in all branches of nanoscience and nanotechnology. Since it is sometimes desirable for single nanomaterials to perform multiple functions simultaneously, multicomponent nanomaterials, such as core-shell, alloyed, and striped nanoparticles, are being more extensively researched. Nanoscientists hope to design multicomponent nanostructures and exploit their inherent multiple functionalities for use in many novel applications. This review highlights recent advances in the synthesis of multisegmented one-dimensional nanorods and nanowires with metal, semiconductor, polymer, molecular, and even gapped components. It also discusses the applications of these multicomponent nanomaterials in magnetism, self-assembly, electronics, biology, catalysis, and optics. Particular emphasis is placed on the new materials and devices achievable using these multicomponent, rather than single-component, nanowire structures. 相似文献
82.
To understand the structural factors that control the adsorption of acid dyes onto cotton (cellulose), the adsorption of 15 acid dyes from water has been studied. An equilibrium exists between dye adsorbed in the cotton and dye in solution, and by measurement of the temperature dependence (277-333K) of the equilibrium constant, the enthalpy and entropy of binding are obtained. For most dyes adsorption is driven by the binding enthalpy, which is ascribed to van der Waals forces. Acid dyes consist of an aromatic core with peripheral solubilizing groups (generally sulfonates). Dyes in which the sulfonates are on one side of the molecule have the largest binding enthalpy. Assuming a binding geometry where the sulfonates protrude into water pools in the bulk amorphous regions and as much as possible of the dye core touches the surface, then a good correlation exists between the binding enthalpy and the summation of 1/r(6) over all the C, N, and O dye atoms, where r is the distance of each atom from the cellulose surface. 相似文献
83.
Complexes of uranium in its IV oxidation state, using cysteine, glycine, serine and aspartic acid as ligands, have been synthesized. Semi-microanalysis of the complexes indicate 1:1 metal to ligand ratio for all the synthesized complexes. Infrared spectra of solid complexes have been employed to establish the groups, coordinated to the metal ion. Effective magnetic moment of the complexes were also estimated. 相似文献
84.
Muhammad Akhyar Farrukh Noureen Siraj Iftikhar Imam Naqvi 《Journal of Saudi Chemical Society》2010,14(2):209-212
Iron has been determined in apple and vegetables spectrophotometrically, by complexing it with xylenol orange. 1:1 complex formed in a highly acidic medium is measured for its absorbance at its λmax of 585 nm. The results have been compared by employing atomic absorption technique. Apples and vegetable samples were collected from local markets of Pakistan. Statistical manipulations, t-test and F-test, were performed and it was found that the results from the two techniques have an excellent agreement. 相似文献
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86.
Xu Zhao Sarah E. Cleary Ceren Zor Nicole Grobert Holly A. Reeve Kylie A. Vincent 《Chemical science》2021,12(23):8105
Heterogeneous biocatalytic hydrogenation is an attractive strategy for clean, enantioselective C X reduction. This approach relies on enzymes powered by H2-driven NADH recycling. Commercially available carbon-supported metal (metal/C) catalysts are investigated here for direct H2-driven NAD+ reduction. Selected metal/C catalysts are then used for H2 oxidation with electrons transferred via the conductive carbon support material to an adsorbed enzyme for NAD+ reduction. These chemo-bio catalysts show improved activity and selectivity for generating bioactive NADH under ambient reaction conditions compared to metal/C catalysts. The metal/C catalysts and carbon support materials (all activated carbon or carbon black) are characterised to probe which properties potentially influence catalyst activity. The optimised chemo-bio catalysts are then used to supply NADH to an alcohol dehydrogenase for enantioselective (>99% ee) ketone reductions, leading to high cofactor turnover numbers and Pd and NAD+ reductase activities of 441 h−1 and 2347 h−1, respectively. This method demonstrates a new way of combining chemo- and biocatalysis on carbon supports, highlighted here for selective hydrogenation reactions.Heterogeneous chemo-bio catalytic hydrogenation is an attractive strategy for clean, enantioselective C X reduction. 相似文献
87.
Sarah J. R. Staton Josemar A. Castillo Thomas J. Taylor Pierre Herckes Mark A. Hayes 《Analytical and bioanalytical chemistry》2013,405(1):351-357
A substantial portion of the atmospheric particle budget is of biological origin (human and animal dander, plant and insect debris, etc.). These bioaerosols can be considered information-rich packets of biochemical data specific to the organism of origin. In this study, bioaerosol samples from various indoor environments were analyzed to create identifiable patterns attributable to a source level of occupation. Air samples were collected from environments representative of human high-traffic- and low-traffic indoor spaces along with direct human skin sampling. In all settings, total suspended particulate matter was collected and the total aerosol protein concentration ranged from 0.03 to 1.2 μg/m3. High performance liquid chromatography was chosen as a standard analysis technique for the examination of aqueous aerosol extracts to distinguish signatures of occupation compared to environmental background. The results of this study suggest that bioaerosol “fingerprinting” is possible with the two test environments being distinguishable at a 97 % confidence interval. Figure
Generalized schematic of human debris-based occupation detection. The various human occupation-related aerosolized material are collected via the filtration assembly along with other non-related aerosolized material. The collected material was then analyzed for total protein concentration as well as coarsely separated to generated unique pattern profiles. These profiles are information-rich enough to identify human occupation in an indoor space 相似文献
88.
Andleeb Z. Naqvi Gamal A. Al-dahbali Mohd. Akram Kabir-ud-Din 《Journal of solution chemistry》2013,42(1):172-189
In the present work, the behavior of mixed drug–surfactant systems has been studied by surface tension measurements. The drug used in this work is adiphenine hydrochloride (ADP) and the surfactants are of m-s-m type geminis, i.e., alkanediyl-α,ω-bis(dimethylalkylammonium bromide), with m = (14, 16), s = (4, 5, 6), and conventional alkyltrimethylammonium bromides (CTAB, TTAB). The excess surface concentration (Γ max ) increases and the minimum head group area at the air/water interface (A min) decreases with increasing concentration of surfactant in the drug solution. Both the critical micelle concentration (cmc) and ideal cmc (cmc*) values decrease with mole fraction of surfactants. Also, the cmc values are lower than cmc*, indicating attractive interactions are present in the mixed micelles. The mole fractions of surfactant in the micelles $ \left( {X_{1}^{m} } \right) $ and monolayers $ \left( {X_{1}^{\sigma } } \right) $ , as well as the respective interaction parameters ( $ \beta^{m} $ , $ \beta^{\sigma } $ ), indicate that monolayer formation is easier than micelle formation due to the rigid hydrophobic part of the drug. 相似文献
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