稀土元素铈(Ce)与氨基酸作用的荧光光谱研究

利用荧光光谱法证明甘氨酸、丙氨酸、谷氨酸、丝氨酸、酪氨酸与稀土Ce4+反应产生了配合物。结果表明与单一的氨基酸相比,甘氨酸、谷氨酸、丙氨酸、丝氨酸4种不含芳环的氨基酸-铈体系出现了明显的荧光发射现象;酪氨酸-铈体系的荧光发射波长发生了明显红移。pH值对各种氨基酸-铈体系的荧光光谱强度影响显著,酸性介质更有利于本论文研究的各种氨基酸与铈离子形成化合物。     

铕(Ⅲ)-4-乙烯基吡啶共聚物稀土高分子配合物的合成及其光物理行为的研究

以4-乙烯基吡啶（4VP）与甲基丙烯酸甲酯（MMA）的共聚物为配体，并以邻菲洛啉（Phen)及2，2′-联吡啶（Bipy)小分子配体协同反应，与Eu(Ⅲ）配位，合成了稀土高分子配合物；通过FTIR表征了配合物的结构；通过紫外光谱与荧光光谱的测定，较充分地研究了稀土高分子配合物光致发光的光物理过程，实验结果表明，4-乙烯基吡啶共聚物通过吡啶环上的氮原子与稀土离子可直接配位；小分子配体的协同配位，可使稀土离子配位数趋于满足，且由于小分子配体能有效地加强能量吸收及分子内的能量传递，大大增强了配合物的荧光强度。     

五种氨基酸钆络合物的ESR波谱

迄今未见任何稀土氨基酸络合物的ESR波谱报道,本文在合成Gd³⁺分别与甘氨酸、β-丙氨酸、谷氨酸、天冬氨酸和天冬酰胺五种氨基酸络合物的基础上,测定了不同温度下,水溶液、粉末及分子筛吸附样品的ESR谱,讨论了络合物中晶体场强,对称性及成键特性。     

溶液燃烧法合成纳米ZnFe2O4晶体

采用溶液燃烧法合成了ZnFe₂O₄纳米晶体,系统考察了不同燃料,燃料/氧化剂的摩尔比对ZnFe₂O₄晶相组成和形貌的影响。采用XRD和SEM对产物的晶相组成、晶粒大小、晶体形貌以及表面形态进行了表征。结果表明:燃料种类和燃料/氧化剂比对合成产物晶相组成影响显著。以丙氨酸和甘氨酸为燃料合成所得的纳米晶相较好;以丙氨酸和甘氨酸为燃料时,都是在贫燃（—50%）时得到最好ZnFe₂O₄纳米晶型,尺寸分别为34.4nm和29.7nm。     

过渡金属-甘氨酸配合物的IR光谱

本文合成了甘氨酸络铜（Ⅱ）、甘氨酸络锌（Ⅱ）和甘氨酸络锰（Ⅱ）3种氨基酸配合物，测定了各配合物的红外光谱，并对它们的谱带进行了详细的归属。     

甘氨酸合铜(Ⅱ)配合物的固、液相反应合成与表征

以固相反应与液相反应两种方法合成了甘氨酸合铜(Ⅱ)配合物,研究了不同研磨时间对甘氨酸合铜(Ⅱ)配合物生成结果的影响.通过元素分析,红外光谱分析,紫外光谱分析,热重-差热等方法对产物进行了表征.实验结果表明,随着固相反应研磨时间的不同,对甘氨酸合铜(Ⅱ)配合物的生成结果有一定的影响,固、液相反应结果基本相同.     

环氧大豆油与丙交酯星形共聚物支化度的表征

采用凝胶色谱(GPC)/示差检测器(RI)/十八角激光光散射仪(MALLS)联用技术, 对环氧大豆油(ESO)与丙交酯形成的星形共聚物(ESO-丙交酯)的结构进行了表征。实验结果表明: 随着ESO-丙交酯星形共聚物分子量的增长, 接枝数目呈现增多趋势、支化度从0.46E-4增大到0.78E-4、支化因子从0.82减小到0.15。本研究为高分子ESO-丙交酯星形支化共聚物的研究提供了科学依据。     

PEO-PPO-PEO嵌段共聚物的NMR研究进展

PEO-PPO-PEO嵌段共聚物是重要的非离子型高分子表面活性剂,在药物载体和基因治疗等领域有着广阔的应用前景. 核磁共振(NMR)作为重要的研究手段,在研究PEO-PPO-PEO嵌段共聚物胶团及液晶结构形成,揭示嵌段共聚物与各种添加剂或药物分子的相互作用机理,有着独特的优势. 本文重点介绍了¹H、¹³C和²H NMR波谱以及NMR弛豫时间和自扩散NMR等技术在研究PEO-PPO-PEO嵌段共聚物体系中的应用. 简要介绍了NMR技术在PEO-PPO-PEO 嵌段共聚物聚集、调控以及作为药物载体等方面的研究现状.     

对－氯苯乙烯和丙烯酸甲酯梯度共聚物的微观结构表征

对由原子转移自由基聚合(ATRP)方法得到的具有“活性”聚合特征的对－氯苯乙烯(S)和丙烯酸甲酯(M)梯度共聚物结构进行了表征．通过¹H、¹³C 核磁共振(NMR)方法和对羰基¹³C峰峰面积的拟合积分研究了该共聚物的单体以及以M为中心的三元组序列结构的组成含量随转化率的变化．研究结果表明：共聚物链中S和M单体含量随着转化率的增加分别表现出减小和增大的变化趋势;三元组序列结构的含量变化中,SMS和MMM分别呈现出单调下降和上升的变化,而MM/MMS则随着转化率的增加达到一个最大值,然后呈现下降趋势．本文还尝试运用了以M为中心的五元组序列结构对羰基¹³C峰峰面积进行更精确的拟合积分,其拟合峰面积的计算结果显示了与上述三元组序列结果相同的变化规律．     

高相对分子质量8-羟基喹啉锂聚合物的制备和性能

高分子电致发光显示器(PLED)是近几年来国际、国内的研究热点,取得了很大的进展,其中高分子化金属配合物是一类很有价值的功能材料。通过甲基丙烯酸甲酯(MMA)、苯乙烯(S)和含有8-羟基喹啉的单体共聚合成模板聚合物,再与氢氧化锂作用,实现了8-羟基喹啉锂配合物的高分子化,获得了一种能够溶解在普通的溶剂中的高相对分子质量的含喹啉锂配合物的发光聚合物,并利用元素分析、¹H-NMR、FTIR、UV、PL光谱、DSC、TGA、GPC等方法对其结构和性能作了表征。紫外吸收和光致发光(PL)光谱说明合成共聚物的发光来自于Liq基团,引入的可聚合的链段以及共聚物中的甲基丙烯酸甲酯或苯乙烯链段,并没有影响发光波长的改变。亲核溶剂改变8-羟基喹啉金属配合物分子结构,使共聚物光谱明显红移20nm左右。     

Preparation and characterization of polyvinyl alcohol—chitosan biocompatible magnetic microparticles

This work addresses the obtaining of biocompatible magnetic polyvinyl alcohol—chitosan microspheres, specifically tailored/functionalised to bind directly blood toxins using an emulsion crosslinking preparation method. The following synthesis parameters were studied: water to oil phase ratio, polyvinyl alcohol molecular weight, chitosan to polyvinyl alcohol weight ratio, surfactant composition and concentration of the crosslinking agent. These parameters were optimized for producing a high yield of colloidally stable and uniformly sized particles with significant magnetization of saturation, bearing surface amino groups that can be further used to bind blood toxins directly. The particles were characterized regarding their size distribution and surface charge (laser diffraction analysis), morphology (transmission electron microscopy), magnetic properties, chemical composition (Fourier transform infrared spectroscopy) and concentration of the surface amino groups (conductometric titration).     

Ultrasonic-assisted synthesis of polyvinyl alcohol/phytic acid polymer film and its thermal stability,mechanical properties and surface resistivity

In this paper, polyvinyl alcohol/phytic acid polymer (PVA/PA polymer) was synthesized through esterification reaction of PVA and PA in the case of acidity and ultrasound irradiation and characterized, and PVA/PA polymer film was prepared by PVA/PA polymer and characterized, and the influence of dosage of PA on the thermal stability, mechanical properties and surface resistivity of PVA/PA polymer film were researched, and the influence of sonication time on the mechanical properties of PVA/PA polymer film was investigated. Based on those, it was concluded that the hydroxyl group on the chain of PVA and the phosphonic group on PA were connected together in the form of phosphonate bond, and the hydroxyl group on the chain of PVA were connected together in the form of ether bond after the intermolecular dehydration; in the meantime, it was also confirmed that PVA/PA polymer film prepared from 1.20 mL of PA not only had the high thermal stability and favorable ductility but also the low surface resistivity in comparison with PVA/PA polymer film with 0.00 mL of PA, and the ductility of PVA/PA polymer film was very sensitive to the sonication time.     

Ultrasonic-microwave assisted synthesis of three-dimensional polyvinyl alcohol carbonate/graphene oxide sponge and studies of surface resistivity and thermal stability

In the article, graphene oxide (GO) was prepared by flake graphite, nitric acid and peroxyacetic acid via the sonochemical method and characterized, and polyvinyl alcohol carbonate/GO composite (PVAC/GO composite) was synthesized by polyvinyl alcohol (PVA), dimethyl carbonate (DMC) and GO via the approach of transesterification in the case of ultrasonic-microwave synergistic effects and characterized, and three-dimensional PVAC/GO sponge (3D PVAC/GO sponge) was manufactured by PVAC/GO composite via the foaming approach and characterized, and the thermal stability and surface resistivity of 3D PVAC/GO sponge were investigated. Based on those, it had been attested that PVAC polymer was structured by DMC and PVA and had the six-membered lactone rings and the ether bonds, and PVAC/GO composite was constituted by 2D GO lattice and PVAC polymer, and 3D PVAC/GO sponge was constructed by PVAC/GO composite, and the surface resistivity of 3D PVAC/GO sponge with 0.00, 0.60, 1.20, 1.80 and 2.40 g of GO were 9.07 × 10⁷, 6.02 × 10⁷, 4.65 × 10⁷, 2.47 × 10⁷ and 1.06 × 107 O/sq, and the thermal stability of 3D PVAC/GO sponge had improved.     

Preparation and optical properties of ZnO@PPEGMA nanoparticles

The poly(poly(ethylene glycol) methyl ether monomethacrylate) (PPEGMA) grafted zinc oxide (ZnO) nanoparticles were successfully prepared via the surface-initiated atom transfer radical polymerizations (ATRP) from the surfaces functionalized ZnO nanoparticles. The 2-bromoisobutyrate (BIB) was immobilized onto the surface of the ZnO nanoparticles through the reaction between 2-bromoisobutyryl bromide (BIBB) and the hydroxyl groups on nanoparticles, serving as the initiator to induce the ATRP of poly(ethylene glycol) monomethacrylate (PEGMA). Well-defined polymer chains were grown from the surfaces to yield hybrid nanoparticles comprised of ZnO cores and PPEGMA polymer shells having multifunctional end groups. The structure and morphology of the nanoparticles were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The optical properties of the nanoparticles were investigated by UV-vis absorption spectroscopy and photoluminescence spectroscopy (PL). The results showed that the dispersion and near-band edge (NBE) emission of ZnO nanoparticles could be improved by the grafted PPEGMA polymer segments.     

Synthesis and characterization of radiation crosslinked nano silver- polyvinyl alcohol/polyethylene oxide composites

Poly (vinyl alcohol)/poly (ethylene oxide) (PEO/PVA) blends were modified by gamma irradiation in the presence of acrylic acid (AAc) monomer. The modified PVA/PEO blends were then complexed with silver nitrate salt and lithium trifluoromethanesulfonate. Transmission electron microscopy was used to determine the distribution as well as the particle size of the silver nanoparticles (NP) formed in the matrix. The UV–vis absorbance spectra of the prepared grafted nanocomposite membranes confirmed the formation of Ag NP based on their surface plasmon band at 438?nm. The electrical properties of the blended electrolyte polymer films were characterized and discussed.     

Synthesis and Characterization of Magnetic Polymer Microspheres

In this study, amino group–modified magnetic polymer microspheres were synthesized in a well‐shaped spherical form with a size range of 0.6 μm to 0.8 μm by mini‐emulsion polymerization. The morphology, composition, and thermal properties of the magnetic polymer microspheres were characterized by infrared (IR) spectra, transmission electron microscopy (TEM) photographs, particle size analysis, and thermogravimetric analysis (TGA) spectra. The results demonstrate that acrylic acid used for stabilizing the reaction system greatly affects the particle size, magnetite contents, and thermal stability of magnetic polymer microspheres.     

Spectral Analysis and Determination of Palladium II Based on the Environment-Friendly and Water-Soluble Polymer

The environment-friendly and water-soluble polymer was prepared via ring-opening reaction between polyvinyl alcohol (PVA) and 3-epoxypropoxy fluorescein (EPF). Based on the quenching of fluorescence signals of PVA–EPF in the 520 nm wavelength and relative quenched intensity is good linear with the concentration of palladium II. A simple, rapid, sensitive, and specific detection method for palladium II is proposed. In comparison with traditionary methods, the present method is environment-friendly, stable, easy to operation, more water-soluble, and cheaper. The results suggested that PVA–EPF may offer potential as a reusable polymer sensor for palladium II ion in aqueous solution.     

Ionic conductivity and dielectric properties of plasticized PVA0.7(LiBr)0.3(H2SO4)2.7M solid acid membrane and its performance in a magnesium battery

This paper describes the synthesis and characterization of a new solid acid polymer electrolyte (SAPE) based on polyvinyl alcohol, lithium bromide and sulfuric acid. Ethylene carbonate was used as plasticizer in the matrix for membranes prepared by a solution cast technique. AC impedance spectroscopy was used to determine the ionic conductivity of SAPE at different temperature and frequency values giving some insight into its potential utility as a solid acid membrane in solid state batteries. The ionic transference number of mobile ions has been estimated by a dc polarization method and the results reveal that the conducting species are predominately ions. A solid state magnesium battery is fabricated and characterized. A cell with the configuration Mg/SAPE/MnO₂ gives a capacity of 270 mAh/g and has an internal resistance ≈ 175 Ω. The electrode degradation after discharge was characterized by XRD analysis.     

氨基酸对纳米硫的表面修饰和形貌调控作用

在超声条件下,向硫的无水乙醇饱和溶液中滴加氨基酸(表面修饰剂)的水溶液制备纳米硫溶胶.所得产物用透射电镜(TEM)、共振瑞利散射光谱(RRS)、激光散射(LLS)等进行表征,分析氨基酸对纳米硫的表面修饰作用机理.结果表明,以氨基酸作为表面修饰剂可在液相中获得具有多种形貌的纳米硫,含硫氨基酸对纳米硫有较好的分散作用,胱氨...     

Scaffold-directed and traceless synthesis of tricyclic quinoxalinone imidazoles under microwave irradiation

Traceless synthesis of 2-aminoimidazoquinoxalinones has been performed on soluble polymer support under open-vessel microwave dielectric heating. The reaction progression is monitored directly by the conventional proton NMR which indicated no release of the substrate from the support. Fmoc-deprotected amino acid polymer conjugates react with 1,5-difluoro-2,4-dinitro benzene to yield polymer bound dinitro fluoro amines, which are further substituted by various primary amines to yield PEG-immobilized dinitrodiamines. Simultaneous reduction of aromatic meta-dinitro group leads to the traceless release of 2-quinoxalinones, followed by N-hetero cyclization with various isothiocyanates in the presence of mercury(II)chloride to furnish 2-aminoimidazoquinolinone rings with three points of diversity at rapid pace.