Nanorod‐assembled FHA microspheres with different F contents were for the first time prepared through a facile one‐step hydrothermal method. The effect of the reaction time and pH value of reaction solutions on the FHA morphology was investigated to elucidate the self‐assembly process of FHA microspheres. The results showed pH values had significant effect on the morphology of the formed FHA crystals, which were self‐assembled into sphere‐like sturctures at high pH conditions and rod‐like structures at low pH values. The results suggested that formation of FHA crystals with varied morphology may be directly related to Ca2+ release kinetics from EDTA‐Ca‐Na2 at different pH conditions. Furthermore, it was found that the chemical stability of FHA microspheres was dependent on the F content in the materials, and high F contents in FHA microspheres lead to improved chemical stability. These results suggest that the prepared self‐assembled FHA microspheres may be used for teeth substitution materials due to their unique hierarchical structures and controllable chemical stability. 相似文献
Zeolitic imidazolate framework-8 (ZIF-8) is synthesized by typical solvothermal method and subsequently calcined under air and nitrogen atmosphere, respectively. The carbon in the calcined ZIF-8 under nitrogen atmosphere was from the carbonization of the guest molecules, without adding any other carbon sources. The samples are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and electrochemical analyzer system. When the ZIF-8 is used as electrode materials for a supercapacitor in 6 M KOH electrolyte, it displays a pseudocapacitive behavior. The untreated ZIF-8 and calcined ZIF-8 under air and nitrogen atmosphere electrodes exhibit a specific capacitance of 96, 156, and 185 F g?1, respectively, at a scan rate of 5 mV s?1 and good stability over 1,500 cycles. These results indicate that the ZIF-8 is a promising material for supercapacitors. 相似文献
By means of the similarity transformation, we discuss the generalized nonlinear Schrödinger equation exhibiting inhomogeneous dispersion, nonlinearity and gain or loss at the same time. Explicit bright and dark multi-similariton solutions are obtained. Based on them, we investigate transmission control using the dispersion decreasing fiber with potential applications to the design of high-speed optical devices and amplifiers and pulse compressors, and the development of tunable sources of amplitude modulated light. 相似文献
A ratiometric fluorescent hybrid nanoprobe CDs-1 for arginine(Arg),exhibiting high sensitivity(the limit of detection,LOD,being 6.5×10^-8 mol/L) and excellent selectivity and anti-interference ability,was fabricated through fluorescence resonance energy transfer(FRET) and the electrostatic attraction between positively-charged hemicyanine molecules and negatively-charged carbon dots(CDs).Arg can be quantitatively detected in the concentration range from 6.0×10^-5 mol/L to 2.7×10^-4 mol/L.Further,due to its ability to target mitochondrion and low cytotoxicity,intracellular Arg was succes s fully tracked through ratiometric fluorescence imaging. 相似文献
Self-organization of ZnO nanoparticles into various superstructures (sheet, platelet, ring) has been achieved with the assistance of micelles formed by surfactant cetyltrimethylammonium bromide (CTAB) under one-pot condition. The CTAB-modified zinc hydroxy double salt (Zn-HDS) mesocrystals act as intermediates to form ZnO hexagonal superstructures at temperatures as low as 50 degrees C. The decomposition temperature of Zn-HDS mesocrystals is much lower than that of the corresponding bulk crystals because the organic additive CTAB effectively decreases the degree of crystallinity. Taking advantage of temperature-induced phase transformation of micelles, two-stage self-organization can form ZnO platelets and ring mesocrystals, that is, ZnO ellipsoidal superstructures formed through vertical attachment on (0001) facets of basic units can further assemble to form ZnO platelets and rings through vertical attachment on (0001) facets of ZnO ellipsoidal superstructures. The structural transformation of micelles as shape templates can offer a new route for self-assembly of nonspherical colloids into three-dimensional photonic crystals. ZnO sheet, ring, and platelet mesocrystals with a high population of polar Zn-(0001) plane are expected to have high photocatalytic activity. 相似文献
Zr-metal organic frameworks (Zr-MOFs, UIO-66) as a kind of crystalline porous material possess controllable porous structure and strong thermal stability up to 753 K. In this paper, we synthesized Ni3(NO3)2(OH)4, Zr-MOF with high specific surface area (1073 m2 g−1) and Ni3(NO3)2(OH)4@Zr-MOF composite for pseudocapacitor material. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were taken to characterize the structure and morphology of Ni3(NO3)2(OH)4, Zr-MOF, and Ni3(NO3)2(OH)4@Zr-MOF. The porous structure of Zr-MOF favors the utilization of the active material Ni3(NO3)2(OH)4 and interfacial charge transport and provides short diffusion paths for ions, which results in a high specific capacitance. Electrochemical properties are evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge measurement. A maximum specific capacitance (SC) of 992 F/g was obtained from CV at a scan rate of 5 mVs−1, which is higher than Zr-MOF (∼134 F g−1) and Ni3(NO3)2(OH)4 (∼753 F g−1). Meanwhile, the Ni3(NO3)2(OH)4@Zr-MOF composite electrode exhibits a good cycling stability over 3000 cycles.