二（2—乙基己基）单硫代磷酸在盐酸介质中萃取钯

在盐酸介质中用二(2-乙基已基)单硫代磷酸萃取钯,其萃取性能随着盐酸浓度增高而降低。用连续变换法、斜率法和饱和法测得萃合物的组成为Pd_2L_3Cl,IR和H'NMR光谱进一步论证了其反应机理为阳离子交换机理;P=S键中的S原子与钯形成配位键。萃取反应如下: 2H_2PdCl_4+3HL(?)H_2Pd_2L_3Cl_3+5HCl     

Triphenylamine- and oxadiazole-substituted poly(1,4-phenylenevinylene)s: synthesis,photo-, and electroluminescent properties

Novel triphenylamine- and oxadiazole-substituted poly(1,4-phenylenevinylene)s (PPV) or CN-PPV (P1–4) were synthesized by the Wittig–Horner, Knoevenagel, and Gilch type polymerization. The polymers exhibited good solubility in common organic solvents, relatively high photoluminescent (PL) efficiency, and high HOMO level for ca. −5.1 eV. The simple double-layer devices of triphenylamine-PPV (P1), ITO/PEDOT: PSS/P1/Cs/Al, exhibited a very high luminance of 510 cd/m² under a low driving voltage of 3 V, demonstrating the effectiveness of triphenylamine moiety as a substituent of PPV derivatives for a light-emitting polymer. Triphenylamine-CN-PPV (P2) exhibited bipolar reversible redox in CV. The bipolar type of PPVs, P2 and triphenylamine-oxadiazole-PPV (P3), showed lower luminance and efficiency than those of the p-type of PPV (P1).     

Poly(cyclopentadienylene vinylene)s: synthesis via ROMP,chemical and physical properties

Norbornene derivatives, bearing different substituents, were polymerized via ring-opening metathesis polymerization (ROMP). This paper mainly reports on possibilities of controlling the stereochemistry of the polymerization reaction to give stereoregular precursors to conjugated polymers. The precursor polymers were then converted to the corresponding conjugated polymers through thermal or base-induced elimination. Monomers used for the polymerization were norbornenebis(methylcarbonate), norbornenebis(S-methyldithiocarbonate) and benzonorbornadienes substituted with isopropylidene, methylbenzylidene, phenylbenzylidene and p-fluorophenyl-p-fluorobenzylidene groups at the bridge carbon. Resulting polymers were then converted to poly(cyclopentadienylene vinylene) or more rigid highly substituted poly(cyclopentadienylene vinylene)-bearing exocyclic double bonds. Characterization was carried out by spectroscopic methods on thin films (photoluminescence, IR, UV-Vis-NIR, ¹H and ¹³C NMR spectroscopy).     

Evolution of the microstructure,chemical composition and magnetic behaviour during the synthesis of alkanethiol-capped gold nanoparticles

In the present paper, we show an exhaustive microstructural characterization of thiol-capped gold nanoparticles (NPs) with two different average particle sizes. These samples are compared with the polymer-like Au(I) phase formed as a precursor during the synthesis of the thiol-capped gold NPs. The set of analysed samples shows different microstructures at the nanoscale with different proportions of Au atoms bonded either to S or to Au atoms. It has been experimentally shown that the presence of a ferromagnetic-like behaviour is associated to the formation of NPs with simultaneous presence of Au–Au and Au–S bonds. In order to explain such magnetic behaviour a possible model is proposed based on the spin–orbit coupling so that localized charges and/or spins (Au–S bonds) can trap conduction electrons (Au–Au bonds) in orbits.     

Intrinsic reactivity of gold nanoparticles: Classical, semi-empirical and DFT studies

Gold nanoparticles used in most experiments (1–10 nm) in gold catalysis show varying degrees of reactivity, with particles below 5 nm generally being more reactive. The origin of this activity is a subject of a number of model experiments and theoretical studies on either clusters of a few atoms in size or extended surfaces (smooth or stepped). In the work described here, a classical theory for the variation of the metal workfunction with cluster size, Extended Hückel Theory (EHT) calculations combined with DFT calculations, as well as a carbon monoxide (CO) chemisorption model are combined to develop a relationship between metal particle size and the particle's reactivity towards CO. For gold, it is shown that while the contribution of the d-band hybridization energy to the total CO chemisorption energy is unfavourable for bulk gold, this is not true for gold particles below 5–6 nm. That is, the d-band hybridization energy is negative for small gold particles. This is believed to be explanation of the onset of high reactivity for small gold particles.     

Preparation of a functional nanofibrous polymer membrane incorporated with poly(2-aminothio phenol) stabilized gold nanoparticles

Functional nanofibrous polymer membranes were prepared by incorporating poly(2-aminothio phenol) (P2AT) stabilized Au NPs onto electrospun polyvinylidene fluoride (PVdF) nanofibers (designated as P2AT-Au NPs@PVdF-NFM). The preparation of P2AT-Au NPs@PVdF-NFM involves two steps: loading of 2AT (monomer) into electrospun PVdF nanofibrous membrane and polymerization of 2AT by gold chloride. P2AT and Au NPs were simultaneously formed into the electrospun PVdF-NFM. Transmission electron microscope image of P2AT-Au NPs@PVdF-NFM informs the presence of Au NPs (with sizes ~10 nm) onto PVdF-NFM.     

Removal and recovery of titanium (IV) from leach liquor of high-sulfur bauxite using calcium alginate microspheres impregnated with di-(2-ethylhexyl) phosphoric acid

In the leaching solution of high-sulfur bauxite roasted by sulfuric acid, a high concentration of aluminum presented along with titanium and iron. The present work was to remove Ti(IV) from the leach liquor by calcium alginate microsphere sorbent material (CA-P204) based on natural alginate impregnated with di-(2-ethylhexyl) phosphoric acid (D2EHPA) to purify leaching solution. Cation exchange and chelation make major contributions to the adsorption mechanism according to Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis. The results showed that Ti(IV) was successfully removed by the CA-P204 adsorbent from the Ti(IV)?Al(III)?Fe(III) ternary system with a dynamic column experiment. The removal rate of titanium was nearly 95% under optimal conditions and the maximum adsorption capacity was 66.79 mg/g at pH 1.0. Reusability of CA-P204 was evaluated over three consecutive adsorption/desorption cycles. The adsorption process was simple, low-cost, and had no waste discharge, suggesting that the CA-P204 was promising, efficient, and economical for removing Ti(IV) from high-sulfur bauxite leaching solution.     

八面体状La2Sn2O7:Eu3+微晶的水热合成、表征与光学性能（英文）

采用水热法在180oC下反应36h合成了具有规整八面体状的烧绿石结构La2Sn2O7:Eu3+微晶。采用XRD、TEM、SEM、EDS、FT-IR、Raman和PL对合成产物的晶体结构、颗粒尺寸、形貌和光学性能进行了研究。对前驱体溶液的pH值、前驱体浓度、水热反应温度和水热反应时间等工艺条件的影响进行了研究。研究结果证实前驱体溶液的pH值不仅决定合成产物的物相结构,而且对合成产物的形貌也具有显著的影响。在pH值为12时可以获得平均尺寸为700nm的规整八面体状晶体。提出了八面体状La2Sn2O7:Eu3+微晶的可能形成机理。光致发光光谱显示:八面体状La2Sn2O7:Eu3+微晶与其它形貌的样品相比较,在582-592nm区域具有更强的发光强度。     

Separation of indium(Ⅲ),gallium (Ⅲ),and zinc(Ⅱ)with Levextrel resin containing di(2-ethylhexyl)phosphoric acid(CL-P204):Part Ⅰ. Selection of separation conditions

A kind of Levextrel resin separation process was developed for separation of indium (Ⅲ), gallium (Ⅲ), and zinc (Ⅱ) from aqueous sulfate solution with Levextrel resin containing di(2-ethylhexyl) phosphoric acid (CL-P204). The aim of the research is to collect preliminary results for a pilot-scale production. Properties of adsorbing indium (Ⅲ), gallium (Ⅲ),and zinc (Ⅱ) from sulfate solution with the Levextrel resin were first studied by batch operation and column operation. The optimum pH, adsorption capacities and concentrations of stripping agents for indium (Ⅲ), gallim (Ⅲ) were tested. The separation order of indium (Ⅲ), gallim (Ⅲ), and zinc (Ⅱ) from sulfate solution with CL-P204 Levextrel resin was found that indium (Ⅲ) could be first separated by adsorbing at the acidity of 1.0 mol/L whereas gallium (Ⅲ) and zinc (Ⅱ) could not, and they were adsorbed together by adsorbing at pH = 2.8, then separated from each other by stripping with 0.1 and 0.5mol/L hydrochloric acid, respectively. The recoveries of three metal ions were all higher than 99%. The cyclic properties of this resin are well.     

Self-assembling into interconnected nanoribbons in thin films of hairy rod poly(9,9-di(2-ethylhexyl)fluorene): Effects of concentration,substrate and solvent

This study utilizes atomic force microscopy to investigate the self-assembling behaviors from dilute solution into thin film of a well-known conjugated polymer, poly(9,9-di(2-ethylhexyl)fluorene) (PF2/6). We have found that the structures of nanoscale aggregates depend on various experimental parameters including concentration, substrate and solvent. The self-assembling of PF2/6 from 0.05 mg/mL solution in toluene onto SiO_x/Si substrate results in the formation of interconnected nanoribbons with thickness and width of about 20 and 150 nm, respectively. Varying polymer concentration and type of substrate (SiO_x/Si or mica) significantly affects the nanoscale structures. The change of solvent to chlorobenzene, a slightly more polar solvent with slower evaporation rate, causes the growth of ribbon width to micron size with slight increase of the thickness. When the solvents with higher evaporation rate (i.e. chloroform and dichloromethane) are used, densely packed nanoribbons are obtained. Its width also grows to micron size. The measurements of UV/vis absorption and photoluminescence spectra detect some discrepancies in pattern, reflecting the variation of local chain organization within thin films prepared by using different solvents.     

Monodisperse magnetic metallic nanoparticles: synthesis, performance enhancement, and advanced applications

Monodisperse Fe-based and Co-based nanopar-ticles exhibit unique magnetic properties. They play important roles in magnetic storage and biomedical application. Their chemical synthesis and performance enhancement draw a lot of study interest. Investigations of magnetic metallic nano-particles are very active in many scientific fields. This paper reviews the present advances in chemical synthesis, perfor-mance enhancement, and potential applications of monodis-perse Fe-based and Co-based nanoparticles.     

Preparation and properties of nanocomposites based on poly(lactic acid) and functionalized TiO2

Inorganic/polymer nanocomposites are significant materials due to their unique combination of properties. Lactic acid (LA) was used to modify the TiO₂ surface by the Ti-carboxylic coordination bonds, and LA can chemically bond TiO₂ nanoparticles to form functionalized oligomeric-poly(lactic acid)-grafted TiO₂ nanoparticles (g-TiO₂). The resulting g-TiO₂ was added to the poly(lactic acid) (PLA) matrix to prepare PLA/TiO₂ nanocomposites via melting processing. The structure and properties of the nanocomposites were subsequently investigated via Fourier transform infrared spectroscopy, gel permeation chromatography, scanning electron microscopy, transmission electron microscopy, polar optical microscopy, differential scanning calorimetry, dynamic rheometer and universal testing machine. The results showed that g-TiO₂ nanocomposites had a much lower degree of agglomeration than bare TiO₂. The introduction of g-TiO₂ into PLA matrix improved the crystallinity of the composites. The functionalized nanoparticles played an important role in improving mechanical properties and reducing the complex viscosity of the nanocomposites due to its unique structure and the reasonable interfacial interaction between the nanoparticles and PLA matrix.     

La2(Zr0.7Ce0.3)2O7固相合成行为及热物理性能

采用固相合成制备了热障涂层陶瓷材料La2(Zr0.7Ce0.3)2O7(LZ7C3)。通过差热分析、X射线衍射等分析方法对固相合成行为影响因素进行研究,并用激光脉冲法和高温膨胀仪测试了LZ7C3粉末的热扩散系数和热膨胀系数。结果表明:完全合成LZ7C3的温度至少1400℃,煅烧时间至少5 h,反应粉末的粒度为0.82μm时,合成的LZ7C3粉末X射线衍射图谱没有La2 O3残留峰,其La∶Zr∶Ce为50.09∶35.12∶14.79,非常接近理论原子比例10∶7∶3;LZ7C3的热导率在1200℃时为0.79 W.m-1.K-1,热膨胀系数在1200℃时为11.6×10-6K-1,从室温到1200℃的加热过程中没有失重和相变发生,具有较高的相稳定性。     

Electrochemical synthesis of oligomers of the mono n-octyl-ester of 3(3-thienyl)glutaric acid and its properties

The structure and properties of electrochemically synthesized oligomers of the mono n-octyl-ester of 3(3-thienyl)glutaric acid (EGA) have been studied. By using UV-Vis, FT-IR, ¹H-NMR, emission as well as simulated UV-Vis and ¹H-NMR spectra of the product it has been found that the trimer of EGA with a non-stereoregular structure of the head-to-head and tail-to-tail type (HT-TT) is formed as a main product after accomplishing the electrosynthesis.     

Synthesis,characterization, and electrochromic properties of conducting poly(hexanedioic acid bis-(2-thiophen-3-yl-ethyl ester) and its copolymer with thiophene

Hexanedioic acid bis-(2-thiophen-3-yl-ethyl) ester (HABTE) was synthesized via the reaction of 3-thiophene ethanol with adipoyl chloride. Resulting monomer was electrochemically homopolymerized in the presence of tetrabutylammonium tetrafluoroborate as the supporting electrolyte, in acetonitrile/borontrifloride ethylether solvent mixture (8:2, v/v). Copolymerization in the presence of thiophene was achieved in TBAFB/AN. Resulting homo and copolymers were characterized via CV, FTIR, DSC, TGA, SEM, and UV–vis Spectroscopy. Spectroelectrochemistry analysis of homopolymer, P(HABTE), reflected electronic transitions at 385, ~600, and ~900 nm, revealing π–π* transition, polaron, and bipolaron band formation, respectively. Switching ability of the homopolymer was evaluated by a kinetic study upon measuring the %T at the maximum contrast point, indicating that PHABTE is a potential material for electrochromic devices.     

Chiral metal nanostructures:synthesis,properties and applications

Chirality,the property that an object cannot coincide with its mirror image arising from lack of mirror symmetry,is ubiquitous in nature at various length scales.The physical and chemical properties are strongly related to the nature of chiral complexes,playing a significant role in various fields such as photonics,biochemistry,medicine and catalysis.In particular,the recent flexible design of chiral metal nanostructures offers one platform for deeply understanding the origin of chirality and on...     

Electrografting of poly(carbazole-co-acrylamide) onto several carbon fibers: Electrokinetic and surface properties

Electrografting onto untreated high modulus (HM) and high strength (HS) carbon fibers as well as on electrochemically oxidized HM carbon fibers was carried out under preparative constant current electrolysis conditions by electrocopolymerizing carbazole-acrylamide. The surface morphology of the electrografted carbon fibers was determined by scanning electron microscopy (SEM). In order to obtain at least some information about the relative surface composition of the electrografted fibers energy dispersive X-ray microanalysis (EDX) was applied. For the characterization of chemical composition FTIR reflectance measurements were performed as well. The electrografted copolymer exhibited good thermal stability, which was determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The efficiency of the electrocopolymerization on carbon fiber surfaces under preparative constant current electrolysis conditions was also supported by electrokinetic measurements.