微生物合成的β-羟基丁酸酯与β-羟基已酸酯共聚物/聚乳酸共混材料(PHBHHx/PLA)的力学性能与生物降解性研究

通过熔融共混法制备了聚乳酸/微生物产β-羟基丁酸酯与β-羟基己酸共聚物的共混物(PLA/PHBHHx).采用拉伸力学试验研究了共混物的力学性能.通过土壤悬浊培养降解法和扫描电子显微镜(SEM)分析对共混材料的生物降解性能进行了研究.实验结果表明,随着PHBHHx含量的增加,共混物的拉伸强度和杨氏模量降低,而生物降解速率却显著提高.但是,在175h之前,重量组成比为20/80的共混物降解速率比纯PHBHHx还要快.综合分析表明,共混材料PLA/PHBHHx的重量比为20/80时,具有优良的力学性能和生物降解性.     

聚(St-DVB)型整体柱的制备及其对蛋白质的色谱分离性能

苯乙烯(St)为单体,二乙烯基苯(DVB)为交联剂,在致孔剂甲苯和十二醇存在下,直接以Ф4.6×50mm色谱柱管为模具,同时在整个反应过程中通过氩气对反应混合物施加一个恒定的压力,通过原位聚合制备了聚(苯乙烯-二乙烯基苯)(PSD)型整体柱。在聚合过程中对反应混合物施加一定的压力,使制备的整体柱表面光滑无凹痕现象,并且使柱子的两头平整不凹陷,有利于提高柱效。本文对整体柱的孔结构及其对蛋白质的分离性能进行了研究。实验结果表明,整体柱内部含有大量类似渠道的大孔,孔径为2μm~3μm,在流速为5ml/min时,背压为7MPa。而且流速对色谱分离效率的影响小,流速从1ml/min增大到3ml/min时,牛血清白蛋白和溶菌酶这两种蛋白质的总分离效能指标K1的值基本保持不变,保持在3.35左右,说明可以通过提高流速实现蛋白质的快速分离。     

气色相谱-质谱法测定化妆品中的氯霉素

氯霉素是一种广谱抗生素,化妆品卫生规范规定氯霉素等抗生素为禁用物质.关于氯霉素的检测多采用高效液相色谱(HPLC)[1]和高效液相色谱-质谱(HPLC-MS)[2] 测定,或者经N,O-双三甲基硅烷基-三氟乙酰胺(BSTFA)、三甲基氯硅烷(TMCS)等硅烷化[3-4]后进行气相色谱(GC)、GC-MS测定.本文建立了采用较为普通的乙酸酐试剂进行衍生化,然后用GC-MS测定的方法.将该法应用于化妆品中氯霉素的检测,取得了较好的效果.     

配合物[Cu2(phen)2](SiW12O40)(H2O)7的合成、晶体结构及电化学分析

The title complex has been synthesized by the reaction of silicotungstic acid, 1,10-phenanthroline (phen) monohydrate and cupric acetate. The crystal structure belongs to triclinic system, space group P1 with a=1.158 46(15) nm, b=1.658 8(2) nm, c=1.664 4(2) nm, α=82.090(2)°, β=76.001(2)°, γ=86.531(2)°, and V=3.072 6(7) nm³, D_c=3.887 g·cm^-3, Z=2, F(000)=3 196. R₁=0.086 7, wR₂=0.185 8. The structure shows that the copper(Ⅱ) atom is coordinated with two nitrogen atoms from the one phen and three oxgygen atoms from three water, forming a distorted square-pyramid configuration The cyclic voltametric behavior of the complex is also reported. CCDC: 298807.     

[Cu(PTA)(Phen)2](p-MBA)(H6O)配合物的合成、晶体结构及电化学分析

The crystal structure of the title complex with the stoichiometric formula [Cu(PTA)(Phen)₂](p-MBA)(H₆O) (Phen=1,10-phenanthroline, PTA=terephthalic acid, p-MBA=p-toluic acid) has been determined by single-crystal X-ray diffraction. The crystal (C₄₈H₄₀CuN₄O₁₀, M_r=896.38) belongs to the monoclinic space group C2/c, with the following crystallographic parameters: a=1.778 6(3) nm, b=1.912 5(3) nm, c=1.389 9(2) nm, β=114.686(2)°, V=4.295 7(12) nm³, D_c=1.386 g·cm^-3, Z=4, μ(Mo Kα)=0.574 mm^-1, F(000)=1 860, final GooF=1.019, R=0.054 0, wR=0.148 3 for 2 644 observed reflections (I>2σ(I)). The crystal structure shows that the copper(Ⅱ) ion is coordinated with two oxygen atoms from one terephthalic acid molecule and four nitrogen atoms from two 1,10-phenanthroline molecules, forming a distorted octahedral coordination geometry. The cyclic voltametric behavior of the complex is also reported. CCDC: 298809.     

三种马来二腈基二硫烯镍(Ⅲ)离子对配合物的制备和结构表征

合成了3种离子对配合物 [1-benzyl-3-bromopyridium]⁺[Ni(mnt)₂]^- (1)，[1-(4′-flurobenzyl)-3-bromopyridiunm]⁺[Ni(mnt)₂]^- (2)，[1-(4′-cholorobenzyl)-3-bromopyridium]⁺[Ni(mnt)₂]^- (3)，(mnt=马来二腈基二硫烯，maleonitrile dithiolate)获得了单晶并解析了它们的单晶结构。     

一个新颖三维配位聚合物Pb(1，4-napdc)(DMF)的合成、结构及热稳定性研究

A novel 3D metal-organic coordination polymer Pb(1,4-napdc)(DMF) (1,4-napdc=naphthalene-1,4-dicarboxylate) was synthesized at room temperature using slow vapor diffusion method to grow single crystal that has been analyzed by X-ray diffraction. The crystal belongs to orthorhombic with space group P2₁2₁2₁. The unit cell parameters are as fellows: a=0.701 3(2) nm, b=1.407 6(3) nm, c=1.521 5(4) nm, V=1.501 8(6) nm³ and Z=4. In the crystal structure of Pb(1,4-napdc)(DMF), the square grids constructed with paddle-wheel units of Pb(Ⅱ) and 1,4-napdc links stack over each other to generate infinite 3D network, which has square apertures (1.158×1.158 nm²) along the crystallographic a-axis. The thermal stability of compound was investigated by differential scanning calorimetry and thermogravimetric analysis. CCDC: 293617.     

锰/钴-二氰胺-4-(1-咪唑基)苯胺三元配合物的合成与结构表征

以二氰胺钠[Na(dca)]和4-(1-咪唑基)苯胺(L)为共配体分别与锰盐和钴盐反应合成了2种新的配合物：零维[Mn(L)₂(dca)₂(H₂O)₂] (1)和二维[Co(L)₂(dca)](dca)_0.5(ClO₄)_0.5·1.5H₂O·MeOH (2)。通过元素分析、红外光谱和X射线单晶衍射对其进行了表征。配合物1属于三斜晶系，P1空间群。配合物2晶体属于正交晶系，Cmcm空间群。配合物1是1个中心对称的单核结构，锰(Ⅱ)离子与分别来自2个dca和2个L配体的4个氮原子以及2个水分子配位，形成八面体配位几何，L和dca均为单齿配位；配合物2是由混合桥dca和L组装成的二维配位聚合物网状结构，相邻的二维网以面对面方式堆积，沿c轴方向形成一维孔道，里面填充着未配位的反离子和溶剂分子。     

Pt3Co核-Pt壳型纳米粒子的制备及磁性

Pt₃Co alloy nanoparticles were prepared by the reduction of H₂PtCl₆ and Co(OOCCH₃)₂ using NaBH₄ as a reducing agent. The Pt₃Co core-Pt shell nanoparticles (Pt₃Co@Pt) were synthesized using hydrogen absorption reduction and characterized by plasma-atomic emission spectrometry (ICP), transmission electron microscopy (TEM), X-ray diffraction (XRD) and SQUID magnetometer. The results show that average size of Pt₃Co@Pt nanoparticles is 3.6 nm with a standard deviation of 0.9 nm. Heating Pt₃Co nanoparticles in air at 700 ℃ for 1 h, Co in Pt₃Co nanoparticles was oxidized to Co₃O₄ and CoO; while no oxidation tendency was detected for Pt₃Co@Pt nanoparticles. The crystallize structure of Pt₃Co@Pt changed from the face centered cube (fcc) to the face centered tetragonal (fct) after the heating treatment. The coercivity of the heated Pt₃Co@Pt reached to 276 Oe at room temperature.     

氢原子在Ti(0001)表面吸附的密度泛函理论研究

用密度泛函理论研究了氢原子的污染对于Ti(0001)表面结构的影响. 通过PAW总能计算研究了p(1×1)、p(1×2)、3^1/2×3^1/2R30[deg]和p(2×2)等几种氢原子覆盖度下的吸附结构, 以及在上述结构下Ti(0001)面fcc格点和hcp格点的氢原子吸附. 结果表明, 在p(1×1)-H、p(1×2)-H、3^1/2×3^1/2R30[deg]-H和p(2×2)-H几种H原子覆盖度下, 以p(1×1)-H结构的单个氢原子吸附能为最大. 在p(1×1)-H吸附结构下, 由于氢原子吸附导致的Ti(0001)表面Ti原子层收缩的理论计算数值分别为-2.85%(hcp吸附)和-4.31%(fcc吸附), 因此实际上最有可能的情况是两种吸附方式都有一定的几率. 而实验中观察到的所谓“清洁”Ti(0001)表面实际上是有少量氢原子污染的表面. 不同覆盖度和氢分压下, 氢原子吸附的污染对Ti(0001)表面结构有极大的影响, 其表面的各种特性都会随覆盖度的不同而产生相应的变化.