Synthesis and characterization of Eu-doped hydroxyapatite through a microwave assisted microemulsion process

Europium doped hydroxyapatite (Eu:HAp) nanosized particles with multiform morphologies have been successfully prepared via a simple microemulsion-mediated process assisted with microwave heating. The physicochemical properties of the samples were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra, and the kinetic decays, respectively. The results reveal that the obtained Eu:HAp particles are well assigned to the hexagonal lattice structure of the hydroxyapatite phase. Additionally, it is found that samples exhibit uniform morphologies which can be controlled by altering the pH values. Furthermore, the samples show the characteristic ⁵D₀–⁷F_1–4 emission lines of Eu³⁺ excited by UV radiation.     

一种纳米氧化锌复合生物基水性聚氨酯的合成和性能研究

以自制的生物基水性聚氨酯(APU)及纳米氧化锌(ZnO)为原料制备了APU/ZnO复合材料,并通过红外光谱(FT-IR)、热重(TG)、紫外(UV)、透射电镜(TEM)和扫描电镜(SEM)等手段对复合材料的性能进行了表征。TEM和SEM照片显示,制得的新型纳米ZnO的尺寸为200 nm左右,可较均匀地分散在APU体系中。TG测试结果表明添加了少量纳米ZnO的复合材料的耐热性有了明显提高。同时测试结果表明,少量纳米ZnO粒子的加入对APU有很好的增强和增韧效果,且具有一定的抗菌性和抗紫外性能。     

A simple method to synthesize polyhedral hexagonal boron nitride nanofibers

Hexagonal boron nitride (h-BN) fibers with polyhedral morphology were synthesized with a simple-operational, large-scale and low-cost method. The sample obtained was studied by X-ray photoelectron spectrometer (XPS), electron energy lose spectroscopy (EELS), X-ray powder diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), etc., which matched with h-BN. Environment scanning electron microscopy (ESEM) and transmission electron microscope (TEM) indicated that the BN fibers possess polyhedral morphology. The diameter of the BN fibers is mainly in the range of 100–500 nm.     

Preparation and Characterization of NiO Nanoparticles Via Solid-State Thermal Decomposition of Nickel(II) Schiff Base Complexes [Ni(salophen)] and [Ni(Me-salophen)]

This study focuses on the preparation and characterization of nickel oxide nanoparticles from nickel(II) Schiff base complexes as new precursors. At first nickel(II) complexes [Ni(salophen)] and [Ni(Me-salophen)] were synthesized and characterized by elemental analyses and FT-IR spectroscopy. Then NiO nanoparticles were prepared by solid-state thermal decomposition at 550 ºC for 3.5 h. The FT-IR spectrum confirmed the composition of products. The crystalline structures and morphology of products were studied by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD results revealed that the obtained products were nickel oxide. SEM and TEM images demonstrated that the NiO nanoparticles have uniform shape with size between 35 and 70 nm.     

Preparation, Characterization and Magnetic Properties of PANI/La-substituted LiNi Ferrite Nanocomposites

Magnetic nanocomposites containing polyaniline （PANI）-coated La-substituted LiNi ferrite （LiNi0.5La0.02Fe1.98O4） were synthesized by in situ polymerization in aqueous solution of hydrochloric acid. The nanocomposites exhibited the magnetic hysteresis nature under applied magnetic field. The saturation magnetization （Ms） and coercivity （Hc） varied with the ferrite content. The obtained nanocomposites were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FT-IR）, UV-Visible spectroscopy and vibrating sample magnetometer （VSM）. TEM and SEM studies showed that the nanocomposites present the core-shell structure. The results of XRD patterns, FT-IR and UV-Visible spectra indicated the formation of PANI-LiNi0.5La0.002Fe1.98O4 nanocomposites and showed that the interaction existed between PANI backbone and ferrite particles in the nanocomposites. The bonding mechanism in the nanocomposites has been proposed.     

A novel chelating acid-assisted thermolysis procedure for preparation of tin oxide nanoparticles

Pure tin dioxide (SnO₂) nanoparticles were synthesized via thermolysis of tin phthalate and tin oxalate in the presence of oleic acid (OA) as solvent. Oleic acid (OA) was employed as an organic solvent, which can be applied to control particle growth and to stabilize the particles. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. The orthorhombic phase SnO₂ nanoparticles with average size about 12 nm were synthesized through thermolysis of tin phthalate in the presence of oleic acid.     

Facile fabrication of cerium niobate nano-crystalline fibers by electrospinning technology

In this study, one-dimensional (1D) cerium niobate nano-crystalline fibers were first prepared by a facile sol–gel and electrospinning process, followed by heat treatment. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HR-TEM) were used to characterize the samples. It can be seen from SEM images that the as-prepared xerogel samples and those annealed at 900 °C presented uniform fibrous morphology, with the diameter of 100–300 nm and length of several centimeters. The XRD and FT-IR results showed that cerium niobate samples had well-crystallized phase of CeNbO_4.25 with the crystallite size of about 28.6 nm at a heat treatment temperature of 900 °C, which can also be validated with the TEM image. The AC impedance of annealed disks made from the CeNbO_4.25 nano-crystalline fibers has been probed.     

Fine tuning of gadolinium doped ceria electrolyte nanoparticles via reverse microemulsion process

Gadolinium doped ceria (Gd–CeO₂) nanoparticles have been synthesized by an reverse microemulsion system using cyclohexane as the oil phase, a non-ionic surfactant Igepal CO 520 and their mixed aqueous solutions of gadolinium III nitrate hexahydrate and cerium III nitrate hexahydrate as the water phase. The control of particle size was achieved by varying the water to surfactant molar ratio. The synthesized and calcined powders were characterized by thermogravimetry-differential thermal analysis (TGA-DTA), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The XRD results show that all the samples calcined at 700 °C were single phase cubic fluorite structure. The average size of the particle was found to increase with increase in water to surfactant molar ratio (R). The mean diameter of the particle for various value of R varies between 8–15 nm (SEM) and 7.5–11 nm (TEM), respectively. EDS confirm the presence of gadolinia and ceria phase in the nanopowder calcined at 700 °C. FTIR analysis was carried to monitor the elimination of residual oil and surfactant phases from the microemulsion-derived precursor and calcined powder. Raman spectroscopy and DTA evidenced the formation of a solid solution of gadolinium doped ceria at room temperature.     

General, room-temperature method for the synthesis of isolated as well as arrays of single-crystalline ABO4-type nanorods

Single-crystalline BaWO(4) and BaCrO(4) nanorods of reproducible shape and of varying sizes have been controllably prepared using a simple, room-temperature approach, based on the use of porous alumina template membranes. Aligned BaWO(4) and BaCrO(4) nanorod arrays can be obtained by dissolving the template. Our facile technique, which is analogous to biomineralization, offers a promising and generalized methodology to prepare other types of free-standing ABO(4) nanorods and their corresponding nanorod arrays. Extensive characterization of these samples has been performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS), selected area electron diffraction (SAED), Raman spectroscopy, FT-infrared spectroscopy (FT-IR), and X-ray diffraction (XRD).     

Synthesis and structural characterization of sol–gel derived titania/poly (vinyl pyrrolidone) nanocomposites

Non hydrolytic sol–gel method was employed to synthesize pure anatase TiO₂ nanocrystals using tetra isopropyl orthotitanate and poly vinylpyrrolidone as precursors. The structural analyses of the prepared samples were carried out using Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric and differential thermal analysis (TG–DTA), X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). The capping of PVP around TiO₂ nanoparticles was confirmed by FT-IR spectroscopy, the interaction being via bridging oxygens of the carbonyl (C=O) and the nanoparticle surface. The XRD, Raman and TEM results indicate that the prepared samples had a pure anatase nano-TiO₂ structure. The particle size analysed by TEM ranged between 7 and 12 nm. The size of the nanocrystals evaluated from the XRD spectra and TEM micrograph is well in agreement. The spacing for the crystal planes was also determined using the ImageJ program applied to the TEM micrographs.     

Characterization of h-WO3 nanorods synthesized by hydrothermal process

Hexagonal tungsten oxide nanorods have been synthesized by hydrothermal strategy using Na₂WO₄·2H₂O as tungsten source, aniline and sulfate sodium as structure-directing templates. Techniques X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy have been used to characterize the structure, morphology and composition of the nanorods. The h-WO₃ nanorods are up to 5 μm in length, and 50–70 nm in diameter.     

Morphologically controlled synthesis of copper oxides and their catalytic applications in the synthesis of propargylamine and oxidative degradation of methylene blue

Alcohol/nonionic polymeric surfactant assisted, morphologically controlled synthesis is developed for micro-/nanostructured crystalline copper oxide. Materials were characterized by a complementary combination of X-ray diffraction (XRD), nitrogen sorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and UV-visible spectroscopy. XRD and FT-IR confirm the formation of a mixture of Cu(OH)₂ and CuO after 0.5 h of hydrothermal treatment and pure CuO after 2 h of hydrothermal treatment. The formation mechanisms were proposed based on the SEM and TEM analysis, which show that both, alcohol/polymeric surfactant and hydrothermal time play an important role in tuning the morphology and structure of CuO. Surface area of metal oxides depends on the alcohols and the nonionic polymeric surfactants used in the synthesis. Surface area of CuO synthesized using methanol was found to be the highest. The catalytic activity of as-synthesized CuO was demonstrated by using three-component coupling reaction in the synthesis of propargylamine and catalytic oxidation of methylene blue in the presence of hydrogen peroxide. Among the CuO prepared in this study, the CuO synthesized using methanol exhibited better catalytic activity (propargylamine yield (64.5%)) and the highest rate of methylene blue degradation (13 × 10⁻³ min⁻¹).     

Mechanical properties of titania nanofiber mats fabricated by electrospinning of sol–gel precursor

Flexible mats of titania fibers are prepared by calcination of electrospun polyvinylpyrrolidone fibers containing titanium isopropoxide precursor. Structural investigation of the calcinated nanofibers by X-ray diffraction (XRD) and electron diffraction (ED) combined with the morphologies by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show the titania fibers, with an average diameter of 180 nm, were comprised of anatase and rutile crystals. The mechanical, chemical and thermal properties of the titania fiber mats are further investigated by the techniques of Instron mechanical tester, thermogravimetric analyzer (TGA), and Fourier transform infrared spectroscopy (FT-IR). The titania fiber mat prepared in this method exhibited a significant flexibility with 461 MPa Young’s modulus.     

A simple route to synthesize nanocrystalline nickel ferrite (NiFe2O4) in the presence of octanoic acid as a surfactant

Nanocrystalline nickel ferrite (NiFe₂O₄) powder was prepared by a co-precipitation method from Ni and Fe chlorides. The as-prepared samples were characterized by powder X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM). SEM and TEM indicated that the particles were spherical with particle sizes in the range 25 ± 5 nm. The magnetic properties of the sample were measured by using a vibrating sample magnetometer, which showed that the sample exhibited typical ferromagnetic behavior at room temperature, while a finite coercivity of 245.5 Oe was present at 300 K. The saturation magnetization of the sample (23.13 emu/g) was significantly lower than that for the reported multidomain bulk particles (55 emu/g), reflecting the ultrafine nature of the sample.     

离子热法制备多级孔AlPO_4-5分子筛

采用离子热法,以磷酸为磷源,γ-Al_2O_3为铝源,在1-丁基-3-甲基溴化咪唑离子液体中于320℃反应10 min内快速合成了多级孔AlPO_4-5分子筛,其结构和形貌经傅里叶红外光谱(FT-IR),X-射线衍射(XRD),扫描电子显微镜(SEM),氮气物理吸-脱附(BET)和透射电镜(TEM)表征。     

Alkyl-terminated crystalline Ge nanoparticles prepared from NaGe: Synthesis, functionalization and optical properties

High purity NaGe was directly prepared by a low-temperature reaction of NaH and Ge. The product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy. This material is a useful starting reagent for the preparation of Ge nanoparticles. Hydrogen-terminated germanium (Ge) nanoparticles were prepared by reaction of NaGe with NH₄Br. These Ge nanoparticles could be prepared as amorphous or crystalline nanoparticles in quantitative yields and with a narrow size distribution. The nanoparticles were functionalized via thermally initiated hydrogermylation with 1-eicosyne, CH₃(CH₂)₁₇C≡CH to produce alkyl-terminated Ge nanoparticles. The modified Ge nanoparticles were characterized by powder XRD, transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and Raman spectroscopy, and photoluminescence (PL) spectroscopy. The alkyl-functionalized Ge nanoparticles can be expected to have promising applications in many technological and biological areas.     

Green biosynthesis of silver nanoparticles using Callicarpa maingayi stem bark extraction

Different biological methods are gaining recognition for the production of silver nanoparticles (Ag-NPs) due to their multiple applications. The use of plants in the green synthesis of nanoparticles emerges as a cost effective and eco-friendly approach. In this study the green biosynthesis of silver nanoparticles using Callicarpa maingayi stem bark extract has been reported. Characterizations of nanoparticles were done using different methods, which include; ultraviolet-visible spectroscopy (UV-Vis), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDXF) spectrometry, zeta potential measurements and Fourier transform infrared (FT-IR) spectroscopy. UV-visible spectrum of the aqueous medium containing silver nanoparticles showed absorption peak at around 456 nm. The TEM study showed that mean diameter and standard deviation for the formation of silver nanoparticles were 12.40 ± 3.27 nm. The XRD study showed that the particles are crystalline in nature, with a face centered cubic (fcc) structure. The most needed outcome of this work will be the development of value added products from Callicarpa maingayi for biomedical and nanotechnology based industries.     

有机膦酸配合物热分解法制备三维网状形貌的偏磷酸铁

用三氯化铁和乙二胺四甲叉膦酸(edtmpH8)为原料合成膦酸铁(FeIII-edtmpH5)配合物前驱体,再将该前驱体在空气氛下焙烧即制得偏磷酸铁Fe(PO3)3.利用电喷雾质谱(ESI/MS)、红外光谱(FT-IR)、热重-差热分析(TG-DTA)测试确定了FeIII-edtmpH5配合物的组成和可能结构.对焙烧后产物进行X射线衍射(XRD)、扫描电镜(SEM)及透射电镜(TEM)测试,结果表明焙烧产物为具有三维网状形貌的高纯Fe(PO3)3.     

The Preparation and Properties of Polyurethane/Nano-CeO<Subscript>2</Subscript> Hybrid Aqueous Coating

To improve the ultraviolet resistance and thermal stability of waterborne polyurethane, stable waterborne polyurethane/nano-cerium oxide hybrid dispersions were obtained by adding nano-cerium colloids to previously synthesized waterborne polyurethane dispersions. The dried ceria colloid was characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The XRD results indicated the prepared CeO₂ was a face-centered cubic structure. The prepared polyurethane/CeO₂ dispersions were studied by dynamic light scattering (DLS), transmission electron microscopy (TEM), UV–Vis spectroscopy and accelerated weathering test. The dried polyurethane/CeO₂ films were characterized using thermogravimetric analysis (TGA). The DLS analysis indicated the particles average diameter of hybrids emulsion was bigger than that of the pure waterborne polyurethane dispersion. TG analysis and accelerated weathering test suggested the hybrid latex films had better thermal stability and mechanical properties than those of the pure waterborne polyurethane. The UV–Vis absorption capacity of the dispersions prepared was increasing with the amount of CeO₂ colloid increased.     

Antibacterial studies of bio-functionalized carbon decorated silver nanoparticles (AgNPs)

In the present report, Lemon juice (bio-extract) extract was efficaciously used for the synthesis of bio-functionalized silver nanoparticles (Ag-1, Ag-2 & Ag-3 NPs) and decorated with carbon material obtained from mustard oil. The morphology, size, crystal structure, formation and interaction were studied by means of innumerable analytical methods including scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy. The XRD results approve the formation of AgNPs with face-centered cubic (fcc) lattice. The XRD results also exhibit some unassigned peaks which might be due to the presence of bio-organic materials on the surface of AgNPs. The bands observed from the IR spectra showing the involvement of biomolecules onto the surface of silver nanoparticles. Mostly citric acid plays a major role in bio-reduction, capping agent, and stabilization of silver ions. We attained maximal inhibition zone (2.10 ​± ​0.05 and 2.03 ​± ​0.027) counter to gram-negative bacteria K. pneumoniae and P. bacilli with Ag-3 respectively, but lowest inhibition zone (1.27 ​± ​0.22) contrary to S. aureus as a gram-positive bacteria with Ag-2.