Influence of Blending Temperature on Fluorescence Properties of Silicone Rubber Matrix Eu(TTA)2(phen)(MA) Composites

A series of fluorescent composites were prepared by blending silicone rubber with Eu(TTA)2(phen)(MA). The influence of mechanical blending temperature on fluorescent intensity of composites and dispersion of rare earth complexes in the SiR matrix were investigated. As for the cured rubber, it is found that its fluorescent intensity is relatively low compared with that of uncured rubber. Low temperature is beneficial to dispersion of Eu(TTA)2(phen)(MA) homogeneously. When the amount of rare earth complexes is low, the fluorescent intensity of composites prepared by mechanical blending method above melting point of Eu(TTA)2(phen)(MA) is much higher than that of composites prepared below melting point.     

RARE EARTH COMPLEXES [Ln(EDBP)2(DME)Na(DME)3] AS CATALYSTS FOR THE POLYMERIZATION OF 2,2-DIMETHYLTRIMETHYLENE CARBONATE

The biphenol based discrete ion-pair rare earth complexes,[Ln(EDBP)<'2>(DME)Na(DME)<'3>] [Ln=Er(1),Yb(2),Sm(3)],were prepared and used as catalysts for the ring-opening polymerization (ROP) of 2,2-dimethyltrimethylene carbonate (DTC).Three complexes show moderate activities for the polymerization,and the catalytic activities increase in the following sequence:(Yb< Er elimination was prepared     

Preparation of Eu （ TTA ）2 phen （ MA ）/SiR Fluorescent Materials under High Mechanical Blending Temperature

Eu（TTA）2（phen）（MA） complexes were synthesized, in which MA was introduced as the acidic ligand to increase the fluorescent intensity of the complexes. The complexes were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and fluorescent spectra, respectively. Different amounts of rare earth complexes were blended with silicon rubber over the melting point of Eu （TTA） 2 （phen） （MA）. Next, a definite amount of 2,5-dimethyl-2, 5-di （tert-butylperoxy） hexane was added as a cross linker to the composite, to get the uncured composites. Subsequently, the composites were vulcanized at 160℃, and silicon rubber-based composites with different contents of the complexes were prepared and their fluorescent properties were observed. The contents of rare earth complexes were 0.96 %, 2.83 %, 4.63 % and 6.36 % （mass fraction）, respectively. Moreover, the composites of Eu （TTA） 2 （phen） （ MA ）/SiR were measured by SEM, XRD, and fluorescent spectra. The measurement result shows that the fluorescent intensity of uncured rubber is similar to one of the pure rare earth complexes. However, there is no marked change of fluorescent intensity in the uncured rubber when the content of rare earth complexes continues to increase.     

丙烯酸稀土盐亚微米粒子制备及其荧光性能研究

用反相悬浮聚合方法 ,在超声分散的条件下 ,以氧化还原体系为引发剂、Span体系为乳化剂制备丙烯酸铕以及丙烯酸铕 (镧 )悬浮液。对体系的稳定性及稀土盐的荧光性能等进行了研究 ,讨论了镧离子和铕离子之间的荧光增强作用 ,并利用扫描电镜观察了粒子的形态和粒径     

Hydrogels in endovascular embolization. VI. Toxicity tests of poly(2-hydroxyethyl methacrylate) particles on cell cultures

Cytotoxicity of poly(2-hydroxyethyl methacrylate) [poly(HEMA)] hydrogel spherical particles, prepared by radical suspension polymerization and designed for endovascular occlusion, was studied in vitro on cell cultures. Testing methods included a direct contact test and extraction test. No inhibition of growth of cells surrounding the poly(HEMA) beads and a very low inhibition of cell viability, only in concentrated extracts in long-term contact, were observed. As a result, poly(HEMA) beads can be considered non-toxic.     

Polymerization of Acrylonitrile with （Diisopropylamido） Bis（indenyl） Lanthanides

Ｔｈｅｒｅａｒｅａｌｏｔｓｏｆｒｅｐｏｒｔｓａｂｏｕｔｔｈｅｐｏｌｙ ｍｅｒｉｚａｔｉｏｎｏｆａｃｒｙｌｏｎｉｔｒｉｌｅ (ＡＮ) [1～ 3] .Ｉｎｔｈｅｒａｄｉｃａｌｐｏｌｙｍｅｒｉｚａｔｉｏｎ ,ｕｓｕａｌｌｙｉｔｉｓｉｎｉｔｉａｔｅｄｂｙｂｅｎｚｏｐｅｒｏｘｉｄｅ ,Ｋ2 Ｓ2 Ｏ4 Ｎａ2 Ｓ2 Ｏ3,Ｆｅ2 + Ｈ2 Ｏ2 ａｎｄｓｏｍｅｏｒｇａｎｉｃｃｏｍｐｏｕｎｄｓ .Ｔｈｅｒｅ ｐｏｒｔｓｏｎｏｒｇａｎｏｌａｎｔｈａｎｉｄｅｓａｓｓｉｎｇｌｅ ｃｏｍｐｏｎｅｎｔｃａｔａｌｙｓｔｓｗａｓｒａｒｅｌｙｉｎｌｉｔｅｒａ…     

Eu(TTA)2(phen)(UAH)/SiR Fluorescence Materials Prepared by In-Situ Reaction Method

Eu(TTA)2(phen)(UAH) (UAH=undecylenic acid)with fine fluorescent property and active group was synthesized. The measurement and characterization of complexes were also carried out. A series of composites based silicon rubber were prepared by blending silicon rubber and Eu(TTA)2(phen)(UAH) rare earth complex with active groups. Next, the effect of vulcanizing time on the property of materials was mainly studied. The results show that the dispersed particle size of rare earth complexes decreases gradually in the vulcanizing process.     

CATIONIC SURFMERS WITH BENZYL GROUPS:SYNTHESIS AND COPOLYMERIZATION WITH ACRYLAMIDE

A series of cationic surfmers with benzyl groups (QARBCs) with different R groups on the benzene ring were synthesized and characterized by IR,<'1>H-NMR,<'13>C-NMR. The aggregation of QARBCs was studied by the steady-state fluorescence technique. It tumed out that QARBCs had surface activity and their cntical micelle concentration (CMC) values varied in the range of 10<'-2>-10<'-3> moI/L with slight increase with temperature. The copolymerization of acrylamide (M<,1>) and QARBCs(M<,2>) was studied below and above CMC,their reactivity ratios were determined by the Finemann-Ross method. It was found that below CMC,copolymerization took place in a homogeneous system and reactivity ratios of acrylamide and QARBCs were less than l;while above CMC,reactivity ratios of QARBCs were greater than l. The copolymerization mechanism of QARBC was observed to be similar to that of micellar polymerization. QARBCs tended to homopolymerization,which gave rise to micro-blocky sequences in the polymer backbone. The Q and e values of QARBCs were calculated according to the Alfrey-Price equation by using r<,1(AM)> and r<,2(QARBO).> Samples of poly(AM-co-QARBC) were prepared above and below CMC and their hydrophobic associations were studied by the steady-state fluorescence spectra and 2D NOESY spectra,and their critical associating concentrations (CAC) were estimated. The results showed that samples of poly(AM-co-QARBC) prepared above CMC had stronger hydrophobic association in aqueous solution than those prepared below CMC.     

热处理工艺对( Mn,Fe)2(P,Si)系列化合物磁性的影响

用机械合金化方法成功制备了Mn1.35Fe0.65 P1-x Six(x=0.56和0.57)化合物,分别采用了两种不同的工艺对化合物进行热处理.用X射线衍射仪、振动样品磁强计和绝热温变测量仪分别对样品的结构、等温磁熵变和绝热温变进行了测量.实验结果表明,经过两种不同热处理工艺处理的化合物都形成了Fe2P型六角结构,空间群为P62m,在经过淬火处理的Mn1..Fe0 eP0..Si0.56化合物中存在少量的(Mn,Fe) 5Si3第二相,空间群为P63/mcm.样品的居里温度都在室温附近,在278 ～296 K之间变化,不同热处理工艺对化合物的居里温度具有一定的影响.经过淬火处理的化合物存在较小的热滞和较大的等温磁熵变,两种化合物的热滞都由自然冷却处理时的5K降低到淬火处理时的3K.当Si的含量分别为0.56和0.57时,与经过自然冷却处理的化合物相比,经过淬火处理的化合物的最大磁熵变分别提升了33％和20％.在经过淬火处理的Mn1.35Fe0.65P0.44Si0.56化合物磁熵变最大,磁熵变的最大值为4.3J·kg-1·K-1.经过自然冷却处理的Mn1.35 Fe0.65P0.44 Si0.56化合物的最大绝热温变为1.2K.低成本的原料、较小的热滞、理想的制冷温区和较大的磁热效应使得Mn1.35 Fe0.65P1-xSix这一系列化合物在室温磁致冷方面有应用前景.     

Interaction of Propagating Radicals with Copper(I) and Copper(II) Species

The effects of copper(I) and copper(II) metal centers on the atom transfer radical polymerization (ATRP) of styrene and methyl acrylate were investigated. The free-radical polymerizations were initiated by AIBN in the presence of copper(I) and copper(II) complexes. For methyl acrylate, the rate of the polymerization was reduced in the presence of CuIBr/dNbpy and CuIOTf/dTbpy but was unaffected by the presence of CuII(OTf)2/dTbpy. For styrene, under conditions which yield relatively low molecular weight polymer (16 000), no effect was observed in the presence of CuII(OTf)2/dNbpy; however, under conditions which yield high molecular weight polystyrene (50 000-100 000), the polymerization was limited in the molecular weight attainable and stopped at partial conversion. No effect was observed for the free-radical polymerization of styrene in the presence of copper(I) complexes. These results indicate that control in ATRP does not originate in interactions of growing radicals with copper complexes but in the reversible halogen atom transfer.     

MmNi5-x(CoAlMn)x/Mg纳米晶复合储氢合金的吸氢性能

研究了机械合金化制备的ＭｍＮｉ５－ｘ（ＣｏＡｌＭｎ）ｘ／Ｍｇ纳米晶复合储氢合金的吸氢特性。通过测定不同镁含量的ＭｍＮｉ５－ｘ（ＣｏＡｌＭｎ）ｘ／Ｍｇ纳米晶复合储氢合金的吸氢ＰＣＴ曲线,考察了镁含量对其吸氢特性的影响。根据对吸氢速度的测定研究了机械合金化对储氢合金的吸氢动力学特性的影响。机械合金化制备的纳米晶复合储氢合金的活化性能与ＭｍＮｉＭ５－ｘ（ＣｏＡｌＭｎ）ｘ铸态合金相比有较大的提高,不需活化或只需一次活化即可吸氢,吸氢量及吸氢的动力学性能与铸态合金相比也有很大的提高。最后对机械合金化形成的纳米晶吸氢特性进行了分析。     

Fluorescence and Judd-Ofelt analysis of rare earth complexes with maleic anhydride and acrylic acid

Two kinds of Eu-complexes, Eu(TTA)2(Phen)(AA) and Eu(TTA)2(Phen)(MA) (HTTA=2-Thenoyltrifluoroacetone, Phen=1,10- phenanthroline, AA=acrylic acid, MA=Maleic anhydride), which combined the excellent fluorescence properties of Eu(TTA)2(Phen)(H2O) and the reactivity of acrylic acid and maleic anhydride with radicals, were synthesized. The two complexes were characterized by elemental analysis, infrared (IR) spectra, and X-ray photoelectron spectroscopy (XPS). Based on the data shown from the fluorescent spectra of the Eu-MA and Eu-AA complexes, the ?λ (λ=2 and 4) experimental intensity parameters were calculated. The results demonstrated that the ?2 intensity parameters for the two complexes were smaller than those for the Eu(TTA)2(Phen)(H2O) complex, indicating that a less symmetri- cal chemical environment existed in the complexes. It implied that the radiative efficiency of the 5D0 of these two complexes could be en- hanced by ligand of MA and AA, respectively. The luminescent lifetime of the Eu-AA (τ=7.26×10–4 s) or Eu-MA complex (τ=8.12×10–4 s) was higher than that of the Eu(TTA)2(Phen)(H2O) complex, which was attributed to the substitution of the water molecule (H2O) in Eu(TTA)2(Phen)(H2O) by the MA or AA ligand.     

稀土配合物[REL3(4-picNO)H2O]的合成与表征

合成了2,3-二氯异丁酸根和4-甲基吡啶氮氧化物稀土三元配合物(RE=La、Ce、Pr、Nd、Sm、Eu).通过元素分析、红外、紫外、荧光、X射线粉末衍射、XPS、热分析以及摩尔电导等分析手段,确定了配合物的组成为[REL3(4-picNO)H2O](L= CH3C2H2Cl2COO -),并对它们的性质进行了讨论.     

Ternary copper complexes and manganese (III) tetrakis(4-benzoic acid) porphyrin catalyze peroxynitrite-dependent nitration of aromatics

Peroxynitrite is a powerful oxidant formed in biological systems from the reaction of nitrogen monoxide and superoxide and is capable of nitrating phenols at neutral pH and ambient temperature. This peroxynitrite-mediated nitration is catalyzed by a number of Lewis acids, including CO2 and transition-metal ion complexes. Here we studied the effect of ternary copper-(II) complexes constituted by a 1,10-phenanthroline and an amino acid as ligands. All the complexes studied accelerate both the decomposition of peroxynitrite and its nitration of 4-hydroxyphenylacetic acid at pH > 7. The rate of these reactions depends on the copper complex concentration in a hyperbolic plus linear manner. The yield of nitrated products increases up to 2.6-fold with respect to proton-catalyzed nitration and has a dependency on the concentration of copper complexes which follows the same function as observed for the rate constants. The manganese porphyrin complex, Mn(III)tetrakis(4-benzoic acid)porphyrin [Mn(tbap)], also promoted peroxynitrite-mediated nitration with an even higher yield (4-fold increase) than the ternary copper complexes. At pH = 7.5 +/- 0.2 the catalytic behavior of the copper complexes can be linearly correlated with the pKa of the phenanthroline present as a ligand, implying that a peroxynitrite anion is coordinated to the copper ion prior to the nitration reaction. These observations may prove valuable to understand the biological effects of these transition-metal complexes (i.e., copper and manganese) that can mimic superoxide dismutase activity and, in the case of the ternary copper complexes, show antineoplastic activity.     

SiO2凝胶玻璃中铕(铽)-邻甲基苯甲酸-邻菲罗啉配合物的热稳定性及发光性能

用溶胶 -凝胶法以掺杂方式制备了含有铕 (铽 ) -邻甲基苯甲酸 -邻菲罗啉配合物的 Si O2 凝胶玻璃复合发光体 ,研究了该复合发光体的荧光和热稳定性。与配合物固体粉末相比较 ,结果表明将配合物引入凝胶玻璃中 ,其热稳定性明显提高 ,而其特征荧光基本保持不变     

Synthesis, Crystal Structure of [ （MeC5H4）2Ln（μ-OCH2 CH2NMe2 ） ]2 （Ln = Sm, Y, Nd） and Their Catalytic Activity for Ring-Opening Polymerization of ε-Caprolactone

Reaction of (MeC5H4)3Ln with HOCH2CH2NMe2 in tetrahydrofuran (THF) gives the new complexes [ (MeC5H4)2Ln(μ-OCH2CH2NMe2)]2(Ln = Sm, Y, Nd) with nitrogen functionalized μ-alkoxide ligand. The complexes were characterized by elemental analysis and IR, and [ (MeC5H4)2Sm(μ-OCH2CH2NMe2)]2 was structurally characterized by the X-ray diffraction to be a dimer formed by two unsymmetric oxygen bridges. The complex has a tricyclic skeleton with the additional two Sm- N bonds via intmmoleeular coordination of OCH2CH2NMe2. The coordination number of the central metal Sm is nine. The tide complexes show good catalytic activity for ring-opening polymerization of ε-capmlactone.     

Preparation of Anhydrous LnCl3(Ln=Eu, Er, Lu) by Chemical Vapor Transport

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LaMg11Zr+200%Ni+x%La(x=O,5,10)储氢合金结构及电化学性能

采用机械合金化法(MA)制备了非晶态LaMg11Zr+200%(质量分数,下同)Ni+x%La(x=0,5,10)系列储氢合金,并详细研究了La添加对该系列合金的相结构及电化学性能的影响.结构分析表明,球磨20h该系列合金都呈非晶态,La添加后合金颗粒得到明显细化;电化学研究表明,La添加后,合金电极充电阻力减小,放电容量随La含量的增加而增大,适量v的添加一定程度上改善了合金电极的循环稳定性和动力学性能,LaMg11Zr+200%Ni+5%La合金电极达到最大放电容量597.2mAh·g-1,循环30次后的容量保持率仍为53.5%.     

Fluorescence Properties of Eu3+/Gd3+/Citric Acid Mixed Complexes Doping in Silicon Rubber Matrix

Series of doped rare earth complexes-EuxGd(1-x)(CA)3·nH2O (CA=citric acid) were synthesized. Some characterizations were taken for these complexes. The experimental results shows that the doped rare earth complexes have the best fluorescence property when the ratio of Eu and Gd is from 0.7 to 0.3. Silicon rubber-based composites were prepared by mechanical blending the EuxGd(1-x)(CA)3·nH2O and silicon rubber. Then, the fluorescent property of the composites was studied. It is found that the fluorescence intensity of the composites increase linearly with the contents of the rare earth complexes increasing.     

Interaction and polymerization of the G-actin-myosin head complex: effect of DNase I

The properties of polymerization and interaction of the G-actin-myosin S1 complexes (formed with either the S1(A1) or the S1(A2) isoform) have been studied by light-scattering and fluorescence measurements in the absence and in the presence of DNase I. In the absence of DNase I, the G-actin-S1(A1) and G-actin-S1(A2) complexes were found to be characterized by different limiting concentrations (l.c.), defined as the complex concentrations above which the polymerization occurs spontaneously within 20 h at 20 degrees C in a "no salt" buffer (l.c. = 0.42 and 8.8 microM for G-actin-S1(A1) and G-actin-S1(A2), respectively). The occurrence of a limiting concentration for either complex together with the kinetic properties of the polymerization led us to conclude that the G-actin-S1 polymerization occurs via a nucleation-elongation process. Fluorescence titrations and proteolysis experiments revealed that G-actin interacts with S1 with a 1:1 stoichiometry (independently of the presence of ATP) with dissociation constants, in the absence of nucleotide, of 20 and 50 nM for the G-actin-S1(A1) and G-actin-S1(A2) complexes, respectively. In the presence of at least a 1.5-fold excess of DNase I, the polymerization of the G-actin-S1 complexes was blocked even at high protein concentration or in the presence of salts. In addition, the affinity of either S1 isoform to actin was reduced 4-5-fold by DNase I, while the stoichiometry of the G-actin-S1 complexes was not changed. However, since the dissociation constants remain in the submicromolar range, we could demonstrate the existence of ternary DNase I-G-actin-S1 complexes stable under polymerizing conditions. Finally, the study of the effect of nucleotides and of various salts on the G-actin-S1 interaction further showed significant differences between the G-actin-S1 and F-actin-S1 interactions.