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1.
A series of novel copolymers of trans-4-hydroxy-L-proline (Hpr) and L-lactide (LLA) were synthesized by ring opening copolymerization, using stannous octoate as a catalyst. These new copolymers have pendant amino functional groups along the polymer backbone chain. Various techniques, including 1H NMR, IR, DSC, and the use of a Ubbelohde viscometer, were used to elucidate structural characteristics, thermal properties, and degradation behavior of the resulting copolymers. Data showed that the optimal reaction condition for the synthesis of the copolymers was obtained using 3 wt% stannous octoate at 140C for 24 h. The DSC analysis demonstrated amorphous structure for most of the copolymers. The glass transition temperatures (T
g) of the copolymers shift to a higher temperature with increasing Hpr/LLA molar ratio. In vitro degradation of these poly(N-CBz-Hpr-co-L-LA) was evaluated by weight loss measurements. 相似文献
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《Journal of Industrial and Engineering Chemistry》2014,20(2):682-688
Copper containing methacrylic polymers were prepared by the polymerization of a copper methacrylate complex (Cu[CH2C(CH3)COO](COD), where COD = 1,5-cyclooctadiene) with different methylmethacrylate and methacrylic acid compositions. These polymers were found to be soluble in many organic solvents including THF and chloroform. Copper nano-networks or aggregated nanoparticles were obtained when a THF solution of the polymers was reduced using an aqueous sodium borohydride solution. When a thin film of the polymers coated on a silicon wafer was irradiated with an electron beam, nanoparticles were produced on the irradiated area, while the non-irradiated areas could be washed away with a weak base developer, such as a tetramethylammoniumhydroxyde (TMAH) aqueous solution, to produce a copper pattern through an electron beam lithography process. 相似文献
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本文建立了一种用高效液相色谱测定反式-反式-2,4-己二烯醇的定量分析方法。它采用Inertsil ODS-SP C18色谱柱,以甲醇-磷酸水溶液(体积比为60∶40)为流动相,流量为1.0 mL/min,柱温为30°C,选择230 nm为检测波长进行检测。结果显示该方法的线性相关系数0.9990,标准偏差为0.092,平均回收率为100.2%。此方法简便、快速、能进行准确定量分析,结果稳定。 相似文献
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O.O.E. Onawumi O.A. Odunola E. Suresh Parimal Paul 《Inorganic chemistry communications》2011,14(10):1626-1631
Two new mixed ligand complexes of copper(II) with acetylacetonate (acac) and 2,2′-bipyridine (bpy) belonging to the class of cytotoxic and antineoplastic compounds known as CASIOPEINAS® have been synthesized and characterized on the basis of analytical and spectroscopic data. Molecular structures of the complexes, [Cu(acac)(bpy)Cl][Cu(acac)(bpy)(H2O]Cl.H2O and [Cu(acac)(bpy)Br]H2O, were established by single crystal X-ray study. The Cu(II) ion in both the complexes exhibited square pyramidal geometry with acac and bpy in the equatorial plane and halide/water in the axial position. Interestingly, for the complex with chloride anion, two types of complexes with chloride and water at the axial positions were derived from the same reaction and co-crystallized in the asymmetric unit with strong intermolecular interactions. Microbial property of these two complexes as antibacterial and antifungal agents has been investigated and some of the results are comparable to that of the standard drugs such as E. coli, P. aeruginosa, S. aureus, S. pyogenes, A. niger and C. albicans, used in this study. 相似文献
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Codeposition of copper and tin from acid sulphate solutions containing polyether sintanol DS-10 and micromolar amounts of halides 总被引:1,自引:0,他引:1
A. Survila Z. Mockus S. Kanapeckait? V. Jasulaitien? R. Jušk?nas 《Electrochimica acta》2007,52(9):3067-3074
Cu(II) and Sn(II) reduction in acid sulphate solutions containing polyether laprol DS-10 was investigated using voltammetric XPS and XRD techniques. Bright yellow bronze coatings can be deposited at potentials (E) that are positive than equilibrium potential () of Sn|Sn2+ electrode. Here, Sn(II) reduction might be treated as underpotential deposition (UPD) of tin on foreign (copper) substrate. Further incorporation of tin into integral Cu-Sn crystallic lattice yields the mixture of pure copper, α-CuSn phase and intermediate hexagonal hcp phase. The formation of free tin phase occurs at . This gives rise for strong inhibitive adsorption of sintanol that manifests itself in the development of deep voltammetric minimum.Addition of halides results in the shift of codeposition potential to more negative values and in the increase of copper content in the coatings deposited in the UPD region. The action of halides intensifies in the sequence Cl− < Br− < I−. If iodide concentration exceeds 2-3 μM, deposition of yellow bronze becomes impossible. 相似文献
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Yat Li Ka-Fu Yung Hoi-Shan Chan Wing-Tak Wong 《Inorganic chemistry communications》2003,6(12):1451-1453
Two copper(I) iodide complexes with polydentate bis(ethylamidophosphine) ligands were synthesized, characterized with crystal structures. They include a dimeric complex [Cu(μ-I)(CH2NHCOC2H4PPh2)2]2 1 containing a planar Cu2I2 rhombohedron with two doubly bridged ligands and a tetrameric complex {Cu4(μ-I)4[(CH2NHCOC2H4PPh2)2]2} 3 with all the coppers and iodines forming a highly distorted cubane geometry. 相似文献
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反式—1,4—聚异戊二烯的热氧老化及防护 总被引:11,自引:3,他引:8
用差示扫描量热法和辊炼实验考察了反式-1,4-聚异戊二烯(TPI)的热氧老化行为,并筛选了防老化体系。测试结果表明,未加防老剂的TPI氧化温度为105℃,氧化表观活化能为76.7kJ/mol;热氧老化类型以断链分解型为主。酚类防老剂264对TPI的有较好的保护效果,加1份即可满足一般储存和加工要求;胺类防老剂4010/RD并用体系也有一定的防护效果。 相似文献
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A number of synergistic solvent extraction (SSX) systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia. These in-clude (1) Versatic 10/CLX50 system for the separation of Ni from Ca in sulphate solutions, (2) Versatic 10/4PC system for the separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (3) Cyanex 471X/HRJ-4277 system for the separation of Zn from Cd in sulphate solutions, (4) Versatic 10/LIX63 system for the separation of Co from Mn/Mg/Ca in sulphate solutions, (5) Versatic 10/LIX63/TBP system for separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (6) Versatic 10/LIX63 system for the separation of cobalt from nickel in sulphate solutions by difference in kinetics, (7) Cyanex 272/LIX84 system for the separation of Cu/Fe/Zn from Ni/Co in sulphate solutions, (8) Versatic 10/LIX63/TBP system to recover Cu/Ni from strong chloride solutions, and (9) Versatic 10/LIX63 system to separate Cu from Fe in strong chloride solutions. The synergistic effect on metal separation and efficiency is presented and possible industrial applications are demonstrated. The chemical stability of selected SSX systems is also reported. 相似文献
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Juan Manuel Lázaro Martínez Gustavo Alberto Monti Graciela Yolanda Buldain 《Polymer》2008,49(25):5482-5489
Novel solid copper(II) complexes were obtained from the polyampholyte poly(EGDE-MAA-IM) and the polyelectrolyte poly(EGDE-MAA) polymers with copper salts at different concentration levels.The materials were characterized employing solid-state Nuclear Magnetic Resonance (NMR), Fourier Transform infrared (FTIR), X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and thermogravimetry (TG).The reticulation induced by MAA in these materials against the poly(EGDE-IM) gel was analyzed by DSC. The coordination behavior of the carboxylic acid of MAA, compared to that provided by the imidazole ring, was studied through solid-state 13C NMR and changes in the FTIR spectra. The non-homogenous character of the doped and undoped materials was analyzed by the glass transition temperature (Tg), 2D 1H-13C WISE NMR and proton spin-lattice relaxation time in the rotating frame (TH1ρ). In particular, the TH1ρ and TH1 values in the complexes decreased with the Cu(II) concentration, showing the high sensitivity of both parameters to the presence of a paramagnetic ion. Finally, the thermogravimetric studies indicated that the presence of the imidazole ring was decisive for the stability of the Cu(II) complexes and for the undoped polymers. 相似文献
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Debasis Senapati G. Roy Chaudhury P. V. R. Bhaskara Sarma 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1994,59(4):335-339
Acidic nickel-bearing solution containing iron, cobalt, manganese, zinc and copper was processed through a solvent extraction and precipitation technique to obtain a pure nickel sulphate solution. Iron was extracted using 0.2M Cyanex-272 (partially neutralised) as the extractant. Stripping of iron from the loaded organic has also been studied. After iron recovery through solvent extraction the raffinate still contained 0·25 g dm?3 of iron which was quantitatively separated by a lime precipitation technique. During this iron precipitation there was no loss of cobalt and nickel but copper, manganese and zinc were coprecipitated to some extent. From the iron-free nickel sulphate solution the other impurities were extracted using the same extractant (Cyanex-272) in a single stage. The metal ions from the loaded organic were stripped using a 0·5% (v/v) H2SO4 solution in a single stage. The entire operation needs only seven stages: two stages for iron extraction, three stages for iron stripping from the loaded organic, and one stage each for extraction and stripping of other impurities. In the entire operation the loss of nickel was less than 0·5%. 相似文献
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《Journal of Sulfur Chemistry》2013,34(1):96-104
Copper(II), cobalt(II) and nickel(II) bis(N-methyl-N-phenyl dithiocarbamate) complexes having the general formula [M{S2CN(MePh)}2] (where M?=?Cu, Co and Ni) have been prepared and characterized by spectral and thermal analysis. The IR spectra suggest that coordination of dithiocarbamate (DTC) occurred through the two sulfur atoms in a symmetrical bidentate fashion. The electronic spectra, conductance measurement and magnetic moment analysis support the proposed geometry for the electronically dilute complexes. The results of the thermal analysis showed that after dehydration, a one-step decomposition pattern leading to the formation of respective metal sulfide as the end-product occurred. The results are consistent with the proposed composition of the complexes. The in vitro antibacterial activity of the complexes was investigated against strains of gram-negative Escherichia coli, Klebsiella oxytoea and Pseudomonas aureginosa, and gram-positive Bacillus cereus, Staphylococcus aureus and Protues mirabilis. The antibacterial activity of the complexes compared favorably with that of streptomycin and augmentine against S. aureus and B. cereus. The cobalt complex had the best antibacterial activity against the test compounds with inhibitory zone range of 11–14.5?mm. 相似文献
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采用溶剂热法合成了一个配合物[Cu(4-Me-SA)(Phen)]•2H2O(Phen = 1,10-邻菲啰啉,4-Me-SA = 4-甲基水杨酸),用X-射线单晶衍射仪测定了该化合物的晶体结构,通过元素分析(EA),红外光谱(FTIR),紫外-可见光谱(UV-Vis),热分析(DSC-TGA)和荧光光谱(FS)对其结构和性质进行了分析与表征。结果表明:晶体属于单斜晶系,P2(1)/c空间群,晶胞参数a = 0.8324(3) nm,b = 1.2644(5) nm,c = 1.7493(7) nm,α = 90.00°,β = 100.404(7)°,γ =
90.00°,V = 1810.8(12) nm3, Z = 4。配位原子分别来自于1个4-甲基水杨酸配体的2个氧原子和1个邻菲啰啉配体的2个氮原子,形成配位数为4的稳定结构。配合物中的氢键和π-π堆积作用使其自组装成1个稳定的三维立体结构。发光性能测试表明该配合物具有荧光性质。 相似文献
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Nisit Tantavichet 《Electrochimica acta》2005,50(9):1849-1861
The influence of plating mode, chloride and thiourea (TU) on morphology of copper deposits has been studied. All experiments were conducted on disc electrodes rotating at 500 rpm and an average current density of 4 A dm−2 to produce 10 μm thick deposits. In additive-free solutions, the use of pulsed current (PC) improved deposit morphology and brightness over DC plating. In the presence of thiourea (no Cl−), the deposits obtained by DC and PC plating were similar under most plating conditions. The presence of thiourea generally improved deposit quality over that obtained in additive-free solutions, but caused the formation of microscopic nodules and the deposits to appear slightly cloudy, resulting in lower reflectances than that of a polished uncoated copper surface. The addition of Cl− to thiourea-containing solutions strongly influenced deposit morphology at both microscopic and macroscopic scales depending on chloride concentration and pulse conditions. It prevented nodule formation and created microscopically bright and reflective deposits, but caused extreme macroscopic roughness. Nevertheless, PC plating at 50 Hz in solutions containing appropriate amounts of thiourea and Cl− was found to yield macroscopically and microscopically smooth deposits with reflectance similar to that of a polished uncoated copper substrate. 相似文献
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Santokh S. Tandon Scott D. Bunge Neil Patel Laurence K. Thompson 《Inorganic chemistry communications》2009,12(10):1077-1080
Reaction between 2,6-diformyl-4-methylphenol (DFMP) and tris(hydroxymethyl)aminomethane (THMAM) with copper(II) acetate and sodium azide formed the antiferromagnetically coupled, polymeric copper(II) coordination cluster {[(H5L)Cu2(μ-N3)]2[Cu(N3)4]·2CH3OH}n (1), with a novel double-stranded ladder like structure in which [Cu(N3)4]2− anions link single-chains comprised of dinuclear subunits, forming a 3D-structure of interconnected ladders through H-bonding. The 3D-structure is the result of coordinatively driven and hydrogen-bonding directed self-assembly. 相似文献