排序方式: 共有8条查询结果,搜索用时 15 毫秒
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Nina Perkas Michael Shuster Galina Amirian Yuri Koltypin Aharon Gedanken 《Journal of polymer science. Part A, Polymer chemistry》2008,46(5):1719-1729
Silver nanoparticles were immobilized on the surface of polypropylene (PP) porous beads by an ultrasound‐assisted reduction method. The structure and properties of the silver–PP composite were characterized with XRD, TEM, HRSEM, EDX, XPS, and Raman spectroscopy. Water‐soluble polymers such as PEG, PVA, and PVP were used as stabilizing agents for preventing the agglomeration of the silver nanoparticles. With PVP, a homogeneous distribution of silver nanocrystals, 50 nm in size, on the PP surface was achieved. The mechanism proposed for the silver anchoring to the inert polymer accounts for a localized melting of the PP. The beads of the silver PP composite demonstrated good stability and high antibacterial activity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1719–1729, 2008 相似文献
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This paper deals with the free vibration analysis of circular alumina (Al2O3) nanobeams in the presence of surface and thermal effects resting on a Pasternak foun- dation. The system of motion equations is derived using Hamilton's principle under the assumptions of the classical Timoshenko beam theory. The effects of the transverse shear deformation and rotary inertia are also considered within the framework of the mentioned theory. The separation of variables approach is employed to discretize the governing equa- tions which are then solved by an analytical method to obtain the natural frequencies of the alumina nanobeams. The results show that the surface effects lead to an increase in the natural frequency of nanobeams as compared with the classical Timoshenko beam model. In addition, for nanobeams with large diameters, the surface effects may increase the natural frequencies by increasing the thermal effects. Moreover, with regard to the Pasternak elastic foundation, the natural frequencies are increased slightly. The results of the present model are compared with the literature, showing that the present model can capture correctly the surface effects in thermal vibration of nanobeams. 相似文献
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Sonochemical irradiation of iron (II) acetate aqueous solution in presence of silver nanopowder resulted in deposition of magnetite nanoparticles on silver nanocrystals, and imparted them with magnetic properties. The Ag-Fe(3)O(4) nanocomposite is well attracted to a permanent magnet, and demonstrates superparamagnetic behavior typical of nanomaterials in a magnetic field. The characterization of the product by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR TEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS) reveal the presence of two phases of the silver and the magnetite, but no chemical interaction between them has been found. The strong anchoring of magnetite to the nanosilver surface was explained as a result of local melting of silver when the magnetite nucleus is thrown at the silver surface by high speed sonochemical microjets. 相似文献
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Ali Nabipour Chakoli Jing Wan Jiang Tao Feng Maryam Amirian Jie He Sui Wei Cai 《Applied Surface Science》2009,256(1):170-177
Up to now, synthetic polymers and biomacromolecules have been grafted or assembled onto the convex surface of carbon nanotubes (CNTs) via covalent bonds or chemisorptions. In this research, poly(l-lactide-co--caprolactone)-functionalized multiwalled carbon nanotubes (MWCNT-OH-g-PCLA)s are synthesized by in situ ring-opening copolymerization of l-lactide (LA) and -caprolactone (CL) using stannous octanoate and hydroxylated MWCNTs (MWCNT-OHs) as the initiating system. The pristine MWCNTs are modified to possess carboxyl groups and then hydroxyl groups. MWCNT-OHs are used as coinitiators to polymerize LA and CL by the surface-initiated ring-opening polymerization. The FT-IR spectra, SEM and TEM micrographs revealed that the PCLA grafted form the sidewall of MWCNTs strongly. The TGA analysis indicates that about 75 wt% of functionalized MWCNTs with PCLA belongs to grafted PCLA and the remaining 25 wt% to the initial MWCNT-OH. 相似文献
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Keller K Amirian A Akcora P 《Langmuir : the ACS journal of surfaces and colloids》2012,28(8):3807-3813
Surfaces grafted with poly(methyl methacrylate) (PMMA) and streptavidin were synthesized through click chemistry to investigate the role of surface stiffness on protein adsorption as the hydrophilic and hydrophobic surface coverage of the substituents vary. Surface topographies coupled with the nanoindentation results indicated that, with the appropriate selections of polymer coverage and chain length, the extent of non-specific protein adhesion could be controlled by the hydrophobic interactions between PMMA, biotin, and streptavidin. It was shown that, when the molecular weight and stiffness of PMMA was close to that of streptavidin, patchy PMMA morphologies were obtained, which help inhibit the non-specific adsorption of streptavidin. 相似文献
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Wang B Karpiouk A Yeager D Amirian J Litovsky S Smalling R Emelianov S 《Optics letters》2012,37(7):1244-1246
Intravascular photoacoustic (IVPA) imaging can characterize atherosclerotic plaque composition on the basis of the optical absorption contrast between different tissue types. Given the high optical absorption of lipid at 1720 nm wavelength, an atherosclerotic rabbit aorta was imaged at this wavelength ex vivo using an integrated intravascular ultrasound (IVUS) and IVPA imaging catheter in the presence of luminal blood. Strong optical absorption of lipid combined with low background signal from other tissues provides a high-contrast, depth-resolved IVPA image of lipid. The ability to image lipid at a single wavelength without removing luminal blood suggests that in vivo detection of lipid in atherosclerotic plaques using combined IVUS/IVPA imaging is possible. 相似文献
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Gerami Alireza Alzahid Yara Mostaghimi Peyman Kashaninejad Navid Kazemifar Farzan Amirian Tammy Mosavat Nader Ebrahimi Warkiani Majid Armstrong Ryan T. 《Transport in Porous Media》2019,130(1):277-304
Transport in Porous Media - No matter how sophisticated the structures are and on what length scale the pore sizes are, fluid displacement in porous media can be visualized, captured, mimicked and... 相似文献
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Fatahi Negin Hoat D. M. Laref Amel Amirian Shirin Reshak A. H. Naseri Mosayeb 《The European Physical Journal B - Condensed Matter and Complex Systems》2020,93(7):1-7
The European Physical Journal B - The present study investigates amplitude death in an oscillator network with asymmetric connection delays and a tree graph topology. A frequency domain analysis... 相似文献
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