Self-assembled 3D flowerlike Lu2O3 and Lu2O3 : Ln(3+) (Ln = Eu, Tb, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures: Ethylene glycol-mediated hydrothermal synthesis and luminescent properties

Three-dimensional flowerlike Lu2O3 and Lu2O3:Ln(3+) (Ln = Eu, Th, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures have been successfully synthesized via ethylene glycol (EG)-mediated hydrothermal method followed by a subsequent heat treatment process. X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectra, thermogravimetric and differential thermal analysis, elemental analysis, inductively coupled plasma atomic absorption spectrometric analysis, ion chromatogram analysis, X-ray photoelectron spectra, scanning electron microscopy, transmission electron microscopy, photoluminescence spectra as well kinetic decays, and cathodoluminescence spectra were used to characterize the samples. Hydrothermal temperature, EG, and CH3COONa play critical roles in the formation of the lutetium oxide precursor microflowers. The reaction mechanism and the self-assembly evolution process have been proposed. The as-formed lutetium oxide precursor could transform to Lu2O3 With their original flowerlike morphology and slight shrinkage in the size after postannealing process.

Synthesis and characterization of magnetic FexOy@SBA-15 composites with different morphologies for controlled drug release and targeting

Magnetic functionalization of the ordered mesoporous SBA-15 (SiO2) aggregate blocks and rice grain-like particles were realized by using a sol-gel method, resulting in the formation of FexOy@SBA-15 composite materials. The X-ray diffraction (XRD), N-2 adsorption/desorption, and transmission electron microscopy (TEM) results show that these composites conserved ordered mesoporous structure after the formation of FexOy nanoparticles in the pores and on the outer surface of SBA-15. It was confirmed by the XRD and X-ray photoelectron spectroscopy (XPS) analysis that the FexOy generated in these mesoporous silica hosts is mainly composed of gamma-Fe2O3. Magnetic measurements reveal that these composites possess superparamagnetic properties at 300 K. The saturation magnetization of these composites increased with the increasing loading amount of gamma-Fe2O3. These composites, which possess high surface area and high pore volume, show magnetic response sufficient for drug targeting in the presence of an external magnetic field.

Electrospinning Synthesis and Luminescence Properties of One-Dimensional Zn2SiO4:Mn2+ Microtibers and Microbelts

One-dimensional Mn2+-doped Zn2SiO4 rnicrobelts and microfibers were prepared by a simple and cost-effective electrospinning process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), energy-dispersive X-ray spectrum (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), and cathodoluminescence (CL) spectra as well as kinetic decays were used to characterize the samples. The XRD and DTA results show that the Zn2SiO4 phase begins to crystallize at 800 degrees C and crystallizes completely around 1000 degrees C. SEM results indicate that the as-prepared microbelts/fibers are smooth, whose diameters decrease with increasing the annealing temperature. The average diameter of the Zn2SiO4:Mn2+ microfibers annealed at 1000 degrees C is 0.32 mu m, and their lengths reach up to several millimeters. The average width and thickness of the Zn2SiO4:Mn2+ microbelts fired at 1000 degrees C are around 0.48 and 0.24 mu m, respectively.

LaF3, CeF3, CeF3 : Tb3+, and CeF3 : Tb3+@LaF3 (core-shell) nanoplates: Hydrothermal synthesis and luminescence properties

LaF3. CeF3, CeF3:Tb3+, and CeF3:Tb3+ @LaF3 (core-shell) 2D nanoplates have been successfully synthesized by a facile and effective hydrothermal process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. The experimental results indicate that the organic additive, trisodium citrate (Cit(3-)), as a shape modifier has the dynamic effect by adjusting the growth rate of different crystal facets, resulting in forming the anisotropic geometries of the final products. The possible formation mechanisms for different products have been presented. The CeF3, CeF3:Tb3+, and CeF3:Tb3+ @LaF3 (core/shell) nanoplates show characteristic emission of Ce3+ (5d-4f) and Tb3+ (f-f), respectively.

Shape-controllable synthesis and upconversion properties of lutetium fluoride (doped with Yb3+/Er3+) microcrystals by hydrothermal process

Lutetium fluorides with different compositions, crystal phases, and morphologies, such as beta-NaLuF4 hexagonal microprisms, microdisks, mirotubes, alpha-NaLuF4 submicrospheres, LuF3 octahedra, and NH4Lu2F7 icosahedra, prolate ellipsoids and spherical particles have been successfully synthesized via a facile hydrothermal route. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, and photoluminescence spectra were used to characterize the samples. The intrinsic structural feature of lutetium fluorides, the solution pH values, F- sources, and organic additives (Cit(3-) and EDTA) account for the ultimate shape evolutions of the final products. The possible formation mechanisms for products with various architectures have been presented. Additionally, we investigated the upconversion luminescence properties of beta-NaLuF4: 20% Yb3+/2% Er3+ with different morphologies.

Synthesis and luminescence properties of monodisperse spherical Y2O3 : Eu3+@SiO2 particles with core-shell structure

Y2O3: Eu3+ phosphor layers were deposited on monodisperse SiO2 particles with different sizes ( 300, 500, 900, and 1200 nm) via a sol-gel process, resulting in the formation of Y2O3: Eu3+@SiO2 core-shell particles. X-ray diffraction ( XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy ( TEM), time-resolved photoluminescence ( PL) spectra, and lifetimes were employed to characterize the Y2O3: Eu3+@SiO2 core-shell samples. The results of XRD indicated that the Y2O3: Eu3+ layers began to crystallize on the silica surfaces at 600 degrees C and the crystallinity increased with the elevation of annealing temperature until 900 degrees C. The obtained core-shell particles have perfect spherical shape with narrow size distribution and non-agglomeration. The thickness of the shells could be easily controlled by changing the number of deposition cycles ( 60 nm for three deposition cycles). Under the excitation of ultraviolet ( 250 nm), the Eu3+ ion mainly shows its characteristic red ( 611 nm, D-5(0)-F-7(2)) emissions in the core-shell particles from Y2O3: Eu3+ shells.

Size-tailored synthesis and luminescent properties of one-dimensional Gd2O3 : Eu3+ nanorods and microrods

Nearly monodisperse and well-defined one-dimensional (1D) Gd2O3:Eu3+ nanorods and microrods were successfully prepared through a large-scale and facile hydrothermal method followed by a subsequent heat treatment process, without using any catalyst or template. X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), photoluminescence (PL) and cathodoluminescence (CL) spectra as well as kinetic decays were used to characterize the samples. The size of the Gd2O3:Eu3+ rods could be modulated from micro- to nanoscale with the increase of pH value using ammonia solution. The as-formed product via the hydrothermal process, Gd(OH)(3):Eu3+, could transform to cubic Gd2O3:Eu3+ with the same morphology and a slight shrinking in size after a postannealing process.

Nanocomposite based on depositing platinum nanostructure onto carbon nanotubes through a one-pot, facile synthesis method for amperometric sensing

Platinum nanoparticles (Pt NPs) were deposited onto multi-walled carbon nanotubes (MWNTs) through direct chemical reduction without any other stabilizing agents. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry were employed to characterize the morphology of the as-prepared nanocomposite (noted as Pt NPs-MWNTs) and further identify the Pt NPs on the surface of MWNTs. The nanocomposite demonstrated the ability to electrocatalyze the oxidation of hydrogen peroxide and substantially raises the response current. A sensitivity of 591.33 mu A mM(-1) cm(-2) was obtained at Pt NPs-MWNTs modified electrode. Thus, we immobilized glucose oxidase (GOD) as a model enzyme on the nanocomposite-based electrode with a thin layer of Nafion to fabricate a glucose biosensor, which showed sensitive and fast response to glucose. The influence of the GOD loading was investigated and the biosensor with an enzyme loading concentration of 10 mg/mL shows optimal performance for glucose detection, that is, a detection limit of 3 mu M and a response time of 3 s, respectively.

One-Step Synthesis of Folic Acid Protected Gold Nanoparticles and Their Receptor-Mediated Intracellular Uptake

We report here a facile method to obtain folic acid (FA)-protected gold nanoparticles (Au NPs) by heating an aqueous solution of HAuCl4/FA in which FA acts as both the reducing and stabilizing agent. The successful formation of FA-protected Au NPs is demonstrated by UV/Vis spectroscopy, transmission electron microscopy (TEM), selected-area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). ne intracellular uptake of these nanoparticles is facilitated by HeLa cells overexpressing the folate reporter, which itself is significantly inhibited by free FA in a competitive assay as quantified by inductively coupled plasma mass spectroscopy (ICP-MS). This simple one-step approach affords a new perspective for creating functional nanomaterials, and the resulting biocompatible, functional Au NPs may find some prospective applications in various biomedical fields.

Synthesis of mesoporous YF3 nanoflowers via solvent extraction route

Mesoporous YF3 nanoflowers were successfully prepared via solvent extraction route. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that these nanoflowers with uneven porous architectures had a spherical shape and were consisted of many YF3 nanosheets with a thickness of about 15 not. Energy-dispersive spectroscopy (EDS) analysis was used to check the chemical composition and purity of the products. YF3 nanoflowers had bimodal mesoporous distribution and Brunauer-Emmett-Teller (BET) surface area of 116 m(2)/g.

Synthesis of REF3 (RE = Nd, Tb) nanoparticles via a solvent extraction route

NdF3 and TbF3 nanoparticles were successfully synthesized via a solvent extraction route using Cynex923 (R3P=O). X-ray diffraction (XRD) study showed that pure hexagonal phase NdF3 and pure orthorhombic phase TbF3 could be obtained under the current synthetic conditions. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observations indicated that as-obtained NdF3 nanoplates have a diameter of 50-80 nm and thickness of 10-20 nm and TbF3 products have sphere morphologies with diameter from 70 to 170 nm. The driving force for the growth of NdF3 nanoplates could be attributed to the hexagonal crystal structure. The luminescence properties of NdF3 and TbF3 nanoparticles were investigated, which indicated that NdF3 nanoparticles showed typical emission at 888,1064, and 1328 nm and TbF3 nanoparticles showed characteristic emission of Tb3+ (f-f).

Synthesis, self-assembly in water, and cytotoxicity of MPEG-block-PLLA/DX conjugates

Docetaxel (DX) is one of the most effective antineoplastic drugs. Its current clinical administration is limited because of its hydrophobicity and Serious side effects. A polymer/DX conjugate is designed and successfully prepared to solve these problems. It is monomethoxy-poly(ethylene glycol)-block-poly(L-lactide)/DX (MPEG-PLLA/DX) It was synthesized by reacting DX with carboxyl-terminated copolymer MPEG-PLLA, which was prepared by reacting succinic anhydride with hydroxyl-terminated copolymer monomethoxy-poly(ethylene glycol)-block-poly (L-lactide) (MPEG-PLLA). Its structure and molecular weight was confirmed by H-1 NMR and GPC. The MPEG-PLLA/DX micelles in aqueous solution were prepared Using a SO]vent displacement method and characterized by dynamic light scattering for size and size distribution, and by transmission electron microscopy for surface morphology. Its antitumor activity against HeLa cancer cells evaluated by MTT assay showed that it had a similar antitumor activity to Pure D at the same drug content.

Type I collagen-mediated synthesis and assembly of UV-photoreduced gold nanoparticles and their application in surface-enhanced Raman scattering

We reported a simple method to synthesize gold nanoparticles (NPs) by photoreducing HAuCl4 in acetic acid solution in the presence of type I collagen. It was found that the collagen takes an important role in the formation of gold NPs. The introduction of collagen made the shape of the synthesized gold nanocrystals change from triangular and hexangular gold nanoplates to size-uniform NPs. On the other hand, thanks to the special characters of collagen molecules, such as its linear nanostructure, are positively charged when the pH < 7, and the excellent self-assembly ability, photoreduced gold NPs were assembled onto the collagen chains and formed gold NPs films and networks. A typical probe molecule, 4-aminothiophenol, was used to test the surface-enhanced Raman scattering activity of these gold NPs films and networks and the results indicated good Raman activity on these substrates.

Synthesis of Titanate-Based Nanotubes for One-Dimensionally Confined Electrical Properties

Structural tailoring for dimensionally confined electrical properties is fundamentally important for nanodevices and the relevant technologies. Titanate-based nanotubes were taken as a prototype one-dimensional material to study. First, Na0.96H1.04Ti3O7 center dot 3.42H(2)O nanotubes were prepared by a simple hydrothermal condition, which converted into Na0.036H1.964Ti3O7 center dot 3.52H(2)O nanotubes by a subsequent acidic rinsing. Systematic sample characterization using combined techniques of X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, electron paramagnetic resonance, Fourier transform infrared spectroscopy, elemental analyses, and alternative current impedance indicated that both nanotubes possessed a scrolled trititanate-type structure with the (200) crystal face predominant on the tube surface. With increasing temperature, both nanotubes underwent a continuous dehydration process, which however imposed different impacts oil the structures and electrical properties, depending on the types of the nanotubes

Synthesis of Ruthenium Dioxide Nanoparticles by a Two-Phase Route and Their Electrochemical Properties

Dissolvable, size- and shape-controlled ruthenium dioxide nanoparticles are successfully achieved through a two-phase route. The influence of reaction time, temperature, and monomer concentration and the nature of capping agents on the morphologies of nanoparticles are studied through transmission electron microscopy (TEM). A possible mechanism for the formation and growth of nanoparticles is also involved. X-ray powder diffraction (XRD) confirms the amorphous structure for as-prepared ruthenium dioxide nanoparticles. Samples are immobilized by simple dip-coating on a current collector, and the cyclic voltammetry measurement is utilized to investigate their electrochemical properties. The specific capacitance of one sample can teach as high as 840 F g(-1), which reveals the promising application potential to electrochemical capacitors.