Biodistribution and toxicity assessment of radiolabeled and DMSA coated ferrite nanoparticles in mice

DMSA-coated Fe₃O₄ nanoparticles were synthesized by wet-chemical method. The chemical interaction between Fe₃O₄ and DMSA were investigated by FTIR. They were directly radiolabeled with ^99mTc radioisotope (Fe₃O₄@DMSA–^99mTc) at room temperature in the presence of stannous solution as a reducing agent. Magnetic and structure properties of Fe₃O₄@DMSA–^99mTc nanoparticles were investigated by AGFM, TEM, and XRD. Biodistribution and toxicity assessment of Fe₃O₄@DMSA–^99mTc were studied in mice by intravenous and intraperitoneally injections, respectively. Blood, kidney, and liver factors were measured 4 days post injection and at the mean-while tissue sections were prepared from their kidney and liver. The results indicate that, the Fe₃O₄@DMSA–^99mTc nanoparticles were passed through the membrane of different cells but do not create any disorder in the kidney and liver function even in high doses such as 300 mg/kg.     

Synthesis and some properties of heteronuclear platinum and palladium carbonyl clusters

Heteronuclear clusters of general formula [Pt_xPd_y(CO) _z] were synthesized by reaction of CO with PtCl₄ + PdCl₂ solutions in 95% ethanol at room temperature and atmospheric pressure. The products isolated were analyzed by IR spectroscopy, thermogravimetry, and X-ray powder diffraction.     

Adsorption Behavior and Reaction Properties of NO and CO on Ir(111) and Rh(111)

Adsorption and reactions of NO over the clean and CO-preadsorbed Ir(111) and Rh(111) surfaces were investigated using infrared reflection absorption spectroscopy (IRAS) and temperature programmed desorption (TPD). Two NO adsorption states, indicative of hollow and atop sites, were present on Ir(111). Only NO adsorbed on hollow sites dissociated to N_a and O_a. The dissociated N_a desorbed as N₂ by recombination of N_a and by a disproportionation reaction between atop-NO and N_a. Preadsorbed CO inhibited atop-NO, whereas hollow-NO was not affected. Adsorbed CO reacted with O_a and desorbed as CO₂. NO adsorbed on the fcc-hollow, atop, and hcp-hollow sites in that order over Rh(111). The hcp-NO was inhibited by preadsorbed atop-CO, and fcc-NO and atop-NO were inhibited by CO preadsorbed on each type of the sites, indicating that NO and CO competitively adsorbed on Rh(111). From the Rh(111) surface-coadsorbed NO and CO, N₂ was produced by fcc-NO dissociation, and CO₂ was formed by reaction of adsorbed CO with O_a from dissociated fcc-NO.     

Protonation of CH3N3 and CF3N3 in Superacids: Isolation and Structural Characterization of Long‐Lived Methyl‐ and Trifluoromethylamino Diazonium Ions

The methylamino diazonium cations [CH₃N(H)N₂]⁺ and [CF₃N(H)N₂]⁺ were prepared as their low‐temperature stable [AsF₆]^? salts by protonation of azidomethane and azidotrifluoromethane in superacidic systems. They were characterized by NMR and Raman spectroscopy. Unequivocal proof of the protonation site was obtained by the crystal structures of both salts, confirming the formation of alkylamino diazonium ions. The Lewis adducts CH₃N₃?AsF₅ and CF₃N₃?AsF₅ were also prepared and characterized by low‐temperature NMR and Raman spectroscopy, and also by X‐ray structure determination for CH₃N₃?AsF₅. Electronic structure calculations were performed to provide additional insights. Attempted electrophilic amination of aromatics such as benzene and toluene with methyl‐ and trifluoromethylamino diazonium ions were unsuccessful.     

稀土乙酰丙氨酸咪唑配合物的合成及光谱性质

稀土元素由于特殊的外层电子构型,在与不同类型配体配位时,呈现出丰富多彩的配位行为和结构,其配合物,特别是有机配合物,由于具有发光性强、选择性好的特点,在发光、激光材料创制、结构探针、荧光免疫分析及生物传感器等领域的研究和应用引起广泛关注.氨基酸、肽是各种生物大分子的基本组成单元,咪唑存在于组氨酸、羧肽酶、血红蛋白等生物分子中参与配位或"变构效应"成为活性部位结构,唑环有丰富的能级,其作为含N富电子体系可与稀土离子形成既有生物活性,又有优良光学性能的配合物.     

Polyvinyl- and polyphenylsilsesquioxanes and their films: an investigation by X-ray diffractometry, positron diagnostics, and 29Si NMR spectroscopy

Polyvinyl- and polyphenylsilsesquioxanes (RSiO_1,5) _n were synthesized by hydrolytic polycondensation. The cross section surface areas of the polymer chain were measured and the sizes of ??traps?? of the free and ordered volumes and the ratio of the T₂ and T₃ units in (RSiO_1,5) _n were determined by time positron diagnostics, ²⁹Si NMR spectroscopy, and X-ray diffractometry. The density of polyvinyl- and polyphenylsilsesquioxanes was determined picnometrically and from the X-ray phase analysis data, and the content of hydroxyl groups was found by thermogravimetry. The cross section surface area of the silsesquioxane chains containing vinyl and phenyl radicals at Si were calculated by the Miller-Boyer method. The elementary volumes of the chain segments determined by different methods were compared. The geometric models for ??traps?? of the free volume were proposed. The optical properties and morphology of the polyvinylsilsesquioxane films were studied by atomic force microscopy and UV spectroscopy.     

Photocatalytic Crystalline and Amorphous TiO2 Nanotubes Prepared by Electrospinning and Atomic Layer Deposition

In this work core/shell composite polymer/TiO₂ nanofibers and from those TiO₂ nanotubes were prepared. First, poly(vinyl alcohol) (PVA) and poly(vinylpyrrolidone) (PVP) fibers were synthetized by electrospinning. They were covered with a 100 nm thick amorphous TiO₂ layer by atomic layer deposition at 50 °C. Later the polymer core was removed by two different methods: dissolution and annealing. In the case of dissolution in water, the as-prepared TiO₂ nanotubes remained amorphous, while when annealing was used to remove the polymers, the TiO₂ crystallized in anatase form. Due to this, the properties of amorphous and crystalline TiO₂ nanotubes with exactly the same structure and morphology could be compared. The samples were investigated by SEM-EDX, ATR-IR, UV-Vis, XRD and TG/DTA-MS. Finally, the photocatalytic properties of the TiO₂ nanotubes were studied by decomposing methyl-orange dye under UV light. According to the results, crystalline anatase TiO₂ nanotubes reached the photocatalytic performance of P25, while amorphous TiO₂ nanotubes had observable photocatalytic activity.     

Na0.33WO3溶胶及薄膜的制备与光致变色性质研究

无机光致变色材料在图像显示、光记录、信息存储和光转换方面有着巨大的潜在应用前景,引起了材料工作者的广泛重视[1￣3]。氧化钨是一种重要的无机光致变色材料,目前对氧化钨的研究多以无定     

Calcium Thiolates and Selenolates: Synthesis and Structures

The synthesis and structural characterization of a family of calcium thiolates and selenolates is described. In the solid state the compounds adopt either contact pairs, as observed in Ca(THF)₄(SMes*)₂ ( 1 ), (Mes* 2,4,6‐tBu₃C₆H₂), and Ca(THF)₄(SeMes*)₂, ( 2 ), or separated ions as shown in [Ca(18‐crown‐6)(HMPA)₂][SeMes*]₂ ( 3 ). The two different ion association modes are induced by addition of specific donors. The compounds were prepared by metalation involving the reaction of elemental calcium dissolved in dry liquid ammonia with either HSMes* or Mes*SeSeMes*. All compounds were characterized by X‐ray crystallography, NMR and IR spectroscopy.     

Ag掺杂型空心TiO2纳米微球的制备与表征及其光催化性能

通过甲基丙烯酸与苯乙烯的乳液聚合制备了表面载有阴离子的聚苯乙烯(PSt)纳米乳胶粒. 在乙醇与水的混合溶剂中, 用硅烷偶联剂乙烯基三甲氧基硅烷对其进行表面改性. 以此乳胶粒为模板, 加入钛酸四丁酯和硝酸银制备了Ag₂O掺杂型聚苯乙烯/二氧化钛(PSt/TiO₂)复合微球. 对该微球在180 °C进行液相预处理、干燥、500 °C煅烧等步骤制备了Ag 掺杂型Ag-TiO₂复合粒子. 通过扫描电镜(SEM)、透射电镜(TEM)和X射线衍射(XRD)等手段对PSt/TiO₂复合粒子及Ag-TiO₂空心粒子的形貌及晶体结构等进行了表征. 考察了Ag-TiO₂复合粒子在紫外光(365 nm)与紫外-可见光(370-760 nm)下对罗丹明B (RhB)降解的催化活性. 结果表明, 与不含银的TiO₂空心微球相比, 在紫外光照射下, 银含量(n_Ag/n_Ti)为0.1%的Ag-TiO₂复合粒子对RhB的降解率提高了11%左右; 在紫外-可见光照射下, n_Ag/n_Ti为1.0%和2.0% 的Ag-TiO₂复合粒子对RhB的降解率提高了30%左右.     

Desolvation and Dehydrogenation of Solvated Magnesium Salts of Dodecahydrododecaborate: Relationship between Structure and Thermal Decomposition

Attempts to synthesize solvent‐free MgB₁₂H₁₂ by heating various solvated forms (H₂O, NH₃, and CH₃OH) of the salt failed because of the competition between desolvation and dehydrogenation. This competition has been studied by thermogravimetric analysis (TGA) and temperature‐programmed desorption (TPD). Products were characterized by IR, solution‐ and solid‐state NMR spectroscopy, elemental analysis, and single‐crystal or powder X‐ray diffraction analysis. For hydrated salts, thermal decomposition proceeded in three stages, loss of water to form first hexahydrated then trihydrated, and finally loss of water and hydrogen to form polyhydroxylated complexes. For partially ammoniated salts, two stages of thermal decomposition were observed as ammonia and hydrogen were released with weight loss first of 14 % and then 5.5 %. Thermal decomposition of methanolated salts proceeded through a single step with a total weight loss of 32 % with the release of methanol, methane, and hydrogen. All the gaseous products of thermal decomposition were characterized by using mass spectrometry. Residual solid materials were characterized by solid‐state ¹¹B magic ‐ angle spinning (MAS) NMR spectroscopy and X‐ray powder diffraction analysis by which the molecular structures of hexahydrated and trihydrated complexes were solved. Both hydrogen and dihydrogen bonds were observed in structures of [Mg(H₂O)₆B₁₂H₁₂] ? 6 H₂O and [Mg(CH₃OH)₆B₁₂H₁₂] ? 6 CH₃OH, which were determined by single‐crystal X‐ray diffraction analysis. The structural factors influencing thermal decomposition behavior are identified and discussed. The dependence of dehydrogenation on the formation of dihydrogen bonds may be an important consideration in the design of solid‐state hydrogen storage materials.     

Electrodeposition and characterization of Cu-TiO2 nanocomposite coatings

Cu-TiO₂ nanocomposites were prepared by electrodeposition method onto copper substrate using an acid copper plating bath containing dispersed nanosized TiO₂. The composition of codeposited TiO₂ nanoparticles in the composite coatings was controlled by the addition of different concentrations of TiO₂ nanoparticles in the bath solution. The average crystallite size was calculated by using X-ray diffraction analysis and it was ~32 nm for electrodeposited copper and ~33 nm for Cu-TiO₂ composite coatings. The crystallite structure was fcc for electrodeposited copper and Cu-TiO₂ nanocomposite coatings. The surface morphology and composition of the nanocomposites were examined by scanning electron microscopy and energy dispersive X-ray spectroscopy analysis. The effect of TiO₂ content on the corrosion and wear resistance properties of the nanocomposite coatings was also presented. The codeposited TiO₂ nanoparticles in the deposit increased the corrosion and wear resistance, which were closely related with TiO₂ content in the nanocomposites. The wear resistance and microhardness of the Cu-TiO₂ nanocomposite coatings were higher than electrodeposited copper. The corrosion resistance property of the electrodeposited copper and Cu-TiO₂ nanocomposite coatings was evaluated by electrochemical impedance and Tafel polarization studies. Cu-TiO₂ composite coatings were more corrosion resistant than electrodeposited copper.     

TG and DSC studies on Sm(III) and Tb(III) tartrates

The tartrate monohydrates of Sm(III) and Tb(III), Sm₂C₁₂H₁₂O₁₈·H₂O and Tb₂C₁₂H₁₂O₁₈·H₂O, were prepared and characterized on the basis of their elemental analysis and IR spectral studies. The thermal decompositions of these compounds, studied by TG and DSC methods, were found to follow an almost uniform pattern. Decomposition occurs in four steps. The first step involves dehydration, accompanied by partial decomposition to the oxalate, followed by conversion to the carbonate. The ultimate product in each case is the oxide M₂O₃, whereM=Sm or Tb. Reflectance spectra of the terbium compound were recorded at various stages of decomposition. The kinetics of the first decomposition step was studied by the non-isothermal method. TG and DSC data for this step were analysed for the evaluation of various kinetic parameters. Reasonable values ofE, Z, andΔS ⁺ were obtained.α vs. T curves were drawn on the basis of the TG and DSC data. The results suggest that the mechanism involves random nucleation.     

Thermal stability and UV-shielding properties of polymethyl methacrylate and polystyrene modified with calcium carbonate nanoparticles

The influences of nanosized CaCO₃ on the thermal and optical properties embedded in poly(methyl methacrylate) (PMMA) and polystyrene (PS) were investigated. Calcium carbonate nanoparticles were synthesized by in situ deposition technique, and its nano size (32–35 nm) was confirmed by scanning electron microscope (SEM) and X-ray studies. Nanocomposites samples of PMMA/CaCO₃ and PS/CaCO₃ were prepared with different filler loading (0–4 wt%) of CaCO₃ nanoparticles by solution mixing technique. The Fourier transform infrared analysis confirmed that CaCO₃ nanoparticles were present in the polymers matrices. The morphology and elemental composition of nanocomposites were evaluated by SEM and energy dispersive X-ray spectroscopy. The thermal properties of nanocomposites were characterized by differential scanning calorimetric, thermogravimetric, and differential thermogravimetry analysis, and the results indicate that the incorporation of CaCO₃ nanoparticles could significantly improve the thermal properties of PMMA/CaCO₃ and PS/CaCO₃ nanocomposites. The glass transition temperature (T _g ) and decomposition temperature (T _d ) of nanocomposites with 4 wt% of CaCO₃ nanoparticles were increased by 30 and 24 K in case of PMMA/CaCO₃ and 32  and 15 K in the case of PS/CaCO₃ nanocomposites, respectively. The obtained transparent nanocomposites films were characterized using UV–Vis spectrophotometer which shows the transparencies of nanocomposites are almost maintained in visible region while the intensity of absorption band in ultraviolet (UV) region is increased with CaCO₃ nanoparticles contents and these composites particles could enhance the UV-shielding properties of polymers.     

Synthesis and characterization of polyaniline/silicon dioxide composites and preparation of conductive films

The focus of this study was to synthesize the inherently conductive polymer polyaniline using an optimized process to prepare polyaniline/silicon dioxide (PANI/SiO₂) composites by in situ polymerization and ex situ solution mixing. PANI and PANI/SiO₂ composite films were prepared by drop‐by‐drop and spin coating methods. The electrical conductivities of HCl doped PANI film and PANI/SiO₂ composite films were measured according to the standard four‐point‐probe technique. The composite films exhibited an increase in electrical conductivity over neat PANI. PANI and PANI/SiO₂ composites were also investigated by spectroscopic methods including UV‐Vis, FT‐IR, and Photoluminescence. UV‐Vis and FT‐IR studies showed that SiO₂ particles affect the quinoid units along the polymer backbone and indicate strong interactions between the SiO₂ particles and the quinoidal sites of PANI (doping effect). The photoluminescence properties of PANI and PANI/SiO₂ composites were studied and the PANI/SiO₂ composites showed increased intensity as compared to neat PANI. The increase of conductivity of PANI/SiO₂ composite may be partially due to the doping or impurity effect of SiO₂ where the silicon dioxides compete with chloride ions. The morphology of particles and films were examined by a scanning electron microscope (SEM). SEM measurements indicated that the SiO₂ were well dispersed and isolated in composite films. Copyright © 2009 John Wiley & Sons, Ltd.     

多孔氧化铝有序膜的制备研究

本文用阳极氧化法分别在硫酸和草酸电解液中成功制备出高度有序、具有纳米级孔洞的氧化铝有序阵列模板。采用饱和HgCl₂去除Al基体后,得到典型六方形结构的多孔Al₂O₃有序膜。通过改变氧化电压、氧化时间等条件使模板的孔径、孔深可调、膜厚度可控,并系统研究了对模板有序性、孔径、膜厚度等的影响因素,总结出制备Al₂O₃有序膜的最佳工艺。     

Synthesis and crystal and defect structures of polycrystalline Cu2SrSnS4 and Cu1.9SrSnS4 powders

The polycrystalline samples of Cu2 – _δSrSnS4 with a trigonal structure were prepared by solid-phase ampoule synthesis with a long annealing time (1944 h), and their crystal lattice parameters were refined and Raman spectra were obtained. For the first time, the effect of defect structure on the lifetimes of photogenerated current carriers in the polycrystalline powders was examined by combining time-resolved microwave photoconductivity and cathodoluminescence methods. A significant increase in the lifetimes during the conversion of Cu₂SrSnS₄ into Cu_1.9SrSnS₄ was found, which was probably due to changes in the defect structure.     

Synthesis and Characterization of Magnesium Pyroborate by Solution Combustion and Conventional Ceramic Methods: A Comparative Study

Solution Combustion Synthesis (SCS) and ConventionalCeramic Process (CCP) were applied for the preparation of magnesium pyroborate (Mg₂B₂O₅) from Mg(NO₃)₂ · 6H₂O and H₃BO₃. Structural and morphological properties of the products were comparatively examined by XRD and FT‐IR spectroscopic measurements as well as SEM and BET techniques. The effects of synthesis conditions on the properties of products were investigated throughly by optimizing the B/Mg molar ratio and reaction duration in CCP and by optimizing the fuel (carbohydrazide) quantity in SCS. Pure Mg₂B₂O₅ (triclinicsuanite) was obtained by thermal treatment in CCP employing a B/Mg molar ratio of 3:1. It was found that the fuel must be in close proximity to the stoichiometric requirements in order to obtain the desired product in highly crystalline form from SCS. The Mg₂B₂O₅ samples obtained by both methods exhibited similar structural properties but different morphologies.     

Synthesis,Characterization,Thermal Decomposition Mechanism and Non—Isothermal Kinetics of the Pyruvic Acid—Salicylhydrazone and Its Complex of Prasseodymium（Ⅲ）

The pyruvic add‐salicylhydrazone and its new complex of Pr(III) were synthesized. The formulae C₁₀H₁₀N₂O₄ (mark as H₃L) and [Pr₂(L)₂(H₂O)₂]·3H₂O (L= the triad form of the pyruvic acid‐salicylhydrazone [C₁₀H₇N₂O₄]^3‐) were determined by elemental and EDTA volumetric analysis. Molar conductance, IR, UV, X‐ray and ¹H NMR were carried out for the characterizations of the complex and the ligand. The thermal decompositions of the ligand and the complex with the kinetic study were carried out by non‐isothermal thermogravimetry. The Kissinger's method and Ozawa's method are used to calculate the activation energy value of the main step decomposition. The stages of the decompositions were identified by TG‐DTG‐DSC curve. The non‐isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by comparing the kinetic parameters.     

Crystal structures and physicochemical properties of mixed salts of ammonium nitrate and sulfate

Mixed salts (NH₄)₂SO₄·2NH₄NO₃ (1) and (NH₄)₂SO₄·3NH₄NO₃ (2) were synthesized and studied by X-ray diffraction analysis. The unit cell parameters of these salts were determined and their crystal structures were solved. The thermal stability of the salts was studied by differential scanning calorimetry and thermogravimetric analysis. The temperatures and enthalpies of incongruent melting of compounds 1 and 2 were determined. The enthalpies of formation from the constituent salts were estimated.