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61.
P-coumaric acid-zinc basic salt nanohybrid for controlled release and sustained antioxidant activity
P-coumaric acid (pCA) has been intercalated in zinc basic salt (ZBS) to design an organic-inorganic nanohybrid material with controlled release and sustained antioxidant activity. According to the powder X-ray diffraction patterns and FT-IR spectra, pCA molecules were intercalated into ZBS without any noticeable alterations in their structural integrity. In vitro release test showed a biphasic discharge of pCA out of the interlayer space of two-dimensional ZBS lattice consisting of an initial burst release followed by a slow and sustained release. The pCA-ZBS nanohybrid exhibited comparable antioxidant activity to that of the free pCA. 相似文献
62.
Yankuan Liu Han Wang Yongchun Zhu Xiaoqing Wang Xiaoyan Liu Haibo Li Yitai Qian 《Solid State Communications》2009,149(37-38):1514-1518
The concentration of the Mn(NO3)2 solution has significant influence on the morphologies and the phases of the MnO2 products. A large number of ε- MnO2 nanowires were prepared via a simple pyrolysis under lower reaction concentration. The nanowires have lengths up to tens of micrometers and diameters in the range of 20–100 nm. The β- MnO2 nanobundles and nanoflowers were prepared by increasing the concentration of Mn(NO3)2 solution. The superparamagnetism of ε- MnO2 nanowires and paramagnetism of β- MnO2 nanoflowers indicate their potential applications in magnetic materials. 相似文献
63.
Bin Yu 《Journal of Physics and Chemistry of Solids》2010,71(4):468-116
Casein, a natural biopolymer contained in milk, has been successfully intercalated into a Ca-Al-LDH host structure. Synthesis was performed by rehydration of tricalcium aluminate in the presence of casein. The resulting nanohybrids were characterized by powder X-ray diffraction (XRD), elemental analysis, infrared spectroscopy (IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Further experiments revealed that the single protein strains intercalate instead of the entire casein sub micelles, which are present in milk. Additionally, the pure phospho protein fractions α- and β-casein, which make up ∼80 wt% of total casein were isolated and intercalated into the Ca-Al-LDH host structure, yielding a biopolymer-inorganic hybrid material. 相似文献
64.
Caterina?Minelli Isabelle?Geissbuehler Rolf?Eckert Horst?Vogel Harry?Heinzelmann Martha?LileyEmail author 《Colloid and polymer science》2004,282(11):1274-1278
We present an extremely versatile method for the lateral organization of nano-scale objects (NOs) based on the phenomenon of polymer demixing. NOs are suspended in a solution of two immiscible polymers, which is used to form a thin polymer film by spin coating. During spin coating the two polymers separate to give a microphase structure, whose length scale depends on the experimental conditions. The NOs spontaneously partition into one or other of the polymer phases resulting in their lateral organization. In this work, the organization of CdSe nanoparticles and fluorescent organic dyes was studied by fluorescence microscopy. The NOs were organized in the polymer film in stochastic patterns or in ordered designs on substrates pre-patterned by soft-lithography techniques. Single-particle measurements, using confocal microscopy, showed that at low concentrations there was little aggregation of the particles. 相似文献
65.
R. Cristescu A. Doraiswamy S. Grigorescu D. Mihaiescu R.J. Narayan I.N. Mihailescu D.B. Chrisey 《Applied Surface Science》2007,253(15):6476-6479
We report the successful deposition of polycaprolactone polymer by MAPLE using a KrF* excimer laser (λ = 248 nm, τ = 7 ns). According to FTIR spectra the deposited films have similar chemical structure to the dropcast material. The fluence plays a key role in optimizing the performances of MAPLE-synthesized polycaprolactone structures. We demonstrated that MAPLE allows for controlling the morphology of films to the level required in targeted drug delivery of pharmacologic agents. 相似文献
66.
Porous flowerlike CeO2 microspheres were synthesized via a novel hydrothermal method and were used as supports for the oxidation of CO. After loaded with Au or CuO, it exhibited an excellent low-temperature catalytic activity toward CO oxidation reaction. Especially, for the Au-loaded flowerlike CeO2 microsphere catalyst, CO gas started its conversion into CO2 above 80% at room temperature. The possible reasons for the superior catalytic activity of flowerlike CeO2 microsphere catalysts were discussed. 相似文献
67.
Jean-Marc Jancu Jean-Christophe Harmand Gilles Patriarche Anne Talneau Karine Meunier Frank Glas Paul Voisin 《Comptes Rendus Physique》2007,8(10):1174-1183
A new attempt to solve the phase matching problem for semiconductor-based frequency conversion devices, based on the implementation of intrinsic birefringence in artificial materials, is discussed. The first results concerning the growth and characterization of ultrashort period superlattices are presented. To cite this article: J.-M. Jancu et al., C. R. Physique 8 (2007). 相似文献
68.
β-Ga2O3 nanoribbons have been prepared by a two-step gas flow control, involving adjusting the pressure inside the tube before and after the formation of the nanoribbons. In different temperature areas, separated nanoribbons and nanowires were obtained, which grew via solid–liquid–vapor–solid (SLVS) and vapor–liquid–solid (VLS) mechanisms, respectively. The samples obtained were characterized by means of scanning electron microscopy, transmission electron microscopy, micro-Raman scattering, and photoluminescence. It was found that Ga2O3 nanoribbons had a perfect monoclinic single-crystal structure with a [002] growth direction. The Ga2O3 nanoribbons give ultraviolet, cyan and green light emission at room temperature under excitation at 254 and 325 nm. 相似文献
69.
Philip Born 《Journal of Physics and Chemistry of Solids》2010,71(2):95-99
Agglomeration of monodisperse thiol-stabilized gold particles with diameters of 6 nm, suspended in organic solvents, was induced by the cooling of the suspension. A sharp transition between the stable suspension and agglomeration resulted. The temperature of the transition depends on the concentration and the compatibility of the solvent. The morphology of the formed particle structures upon agglomeration implies that the used metal colloid can be described as a van der Waals-gas. The particles undergo phase transitions from a stable fluid phase to a metastable phase, in which nucleation and growth occur, or to an instable phase, in which spinodal decomposition occurs. The results will direct research on routes to nanostructured materials using nanoparticles as building blocks. 相似文献
70.
Serge Zhuiykov 《Ionics》2009,15(4):507-512
In situ Fourier transform spectroscopy (FTIR) was used to study interactions of nanostructured ruthenium oxide (RuO2) thin-film sensing electrode with O2 at room temperature. RuO2 nanostructures were pretreated at 1,000 °C for 1 h in order to obtain good crystallinity of amorphous RuO2 nanoparticles. Morphology and properties of nanostructured RuO2 were characterized by X-ray diffraction, thermo-gravimetric/differential thermal analysis, scanning electron microscopy,
and FTIR. It was shown that pretreated RuO2 is quite active for O2
−, O2
2−, and O2− adsorption with clear 722 cm−1 band for superoxide ions (O2
−) adsorption for the different oxygen concentrations. The results of in situ FTIR measurements revealed that the active sites
for oxygen adsorption are not limited to the triple boundaries, but extended to surfaces of RuO2 electrodes. Fundamental vibration frequencies of ruthenium–oxygen bond at a temperature of 23 °C as well as region above
fundamental frequencies for the nanostructured RuO2 were identified. 相似文献