PVP/PVA半互穿网络材料的制备及其性能研究

以N-乙烯基吡咯烷酮(NVP)为单体、N,N-亚甲基双丙烯酰胺(BIS)为交联剂、过硫酸铵(APS)为引发剂,在聚乙烯醇(PVA)水溶液中原位聚合制备了半互穿网络结构(semi-IPN)的复合聚合物,并用红外光谱、表面接触角、吸水率以及拉力测试对材料的结构和性能进行了表征。结果表明：所制备的材料具有温敏特性,当交联剂用量达到一定值时,semi-IPN膜的伸长率和弹性模量都存在一个最大值;增加PVA的用量,semi-IPN膜的表面接触角减小,伸长率和弹性模量则增加明显。     

自降解屏蔽暂堵剂PAM/PCL的合成及性能研究

针对生物降解塑料聚己内酯（PCL）耐温性能差、高温条件下降解时间快等缺点,本文以丙烯酰胺（AM）和PCL为主要原料,N,N-亚甲基双丙烯酰胺（MBA）为交联剂、过硫酸铵（APS）和亚硫酸氢钠（SHS）为引发剂、失水山梨糖醇脂肪酸酯（Span-80）和乙基纤维素为分散剂,采用反相悬浮聚合法合成了一种自降解暂堵剂,考察了分散剂、搅拌速度、交联剂、油水比和引发剂对暂堵剂降解时间的影响,确定了暂堵剂最佳合成条件：分散剂用量（质量分数,下同）0.4%、搅拌速度400 r·min^-1、油水比（体积比）8:2、交联剂用量0.8%、引发剂用量0.5%。对暂堵剂的性能进行了评价,实验结果表明：暂堵剂具有较好的耐温耐盐性,耐温可达160 ℃,与钻井液配伍性较好,少量暂堵剂就可以有效降低钻井液的滤失量。砂床封堵实验表明：暂堵剂具有较好的封堵性能,暂堵剂用量为0.5%就可使砂床浸入深度减少6.5 cm。     

Vp/TAIC共聚物的合成、结构及对麻醉药品吸附性能研究

乙烯基吡咯烷酮为单体(Vp),三烯丙基异氰尿酸酯(TAIC)为交联剂,在混合致孔剂二甲亚砜和乙酸丁酯存在下,用悬浮聚合法制得一系列交联大孔(VpT)共聚物。测定了共聚物的孔结构参数及其对吗啡等麻醉药物的吸附性能。     

丙烯酸酯类吸油树脂的合成与性能研究

以丙烯酸酯、甲基丙烯酸酯为主要单体,二丙烯酸丁二醇酯为交联剂,过氧化二苯甲酰为引发剂,采用悬浮聚合方法,合成聚丙烯酸酯类高吸油树脂.研究了分散剂、引发剂、交联剂用量及单体配比等因素对树脂吸油性能的影响.结果表明,分散剂用量为单体质量的0.12%,引发剂用量为1.0%,交联剂用量为1.5%时树脂的吸油能力最佳,吸甲苯倍率可达15倍,吸汽油倍率可达10倍,吸机油倍率可达近9倍.     

大孔交联甲基丙烯酸缩水甘油酯共聚物的合成及其结构性能研究(Ⅰ)

甲基丙烯酸缩水甘油酯（GMA）为单体，三烯丙基氰尿酸酯（TAC）为交联剂，在致孔剂甲苯、正庚烷存在下，用悬浮聚合法制得一系列大孔共聚物（GT）。测定了共聚物的孔结构性能，讨论了不同交联剂及致孔剂用量和配比对共聚物结构的影响，并初步讨论了特大孔共聚物的形成机理。     

窄分散大粒径交联聚苯乙烯功能微球的合成研究

用分散聚合法，以聚乙烯吡咯烷酮（PVP）为稳定剂，偶氮二异丁腈（AIBN）为引发剂，乙二醇二甲基双丙烯酸酯（EGDMA）为交联剂，一次加料法在醇水介质中制备数个微米交联聚苯乙烯（PS）微球。研究了苯乙烯（St)、丙烯酸（AA）、EGDMA的用量对粒子大小，粒径分布的影响。测量了微球表面羧基的含量。     

P（DMAA-co—AM）水凝胶制备及其固定a-淀粉酶研究

采用氧化还原引发体系,水溶液聚合法制备P（DMAA-co-AM）水凝胶,并以其作为载体固定a-淀粉酶。采用单一变量法研究交联剂（N,N＇-亚甲基双丙烯酰胺）用量、引发剂（过硫酸铵）用量、单体浓度和单体配比对凝胶性能的影响。以水凝胶的最大平衡溶胀度为指标,得出制备P（DMAA-co-AM）水凝胶的优化条件：交联剂用量为0．3％,引发剂用量为0．6％,单体浓度为20％,N,N’-二甲基丙烯酰胺与丙烯酰胺的摩尔比为2：1。在优化条件下,采用原位聚合法固定a-淀粉酶,测定不同单体配比的P（DMAA-co-AM）水凝胶固定化a-淀粉酶的活性。     

两亲性嵌段共聚物PCL-b-PNVP的合成及其自组装行为的研究

以4-羟基-2,2,4,4-四甲基哌啶氮氧自由基为引发剂,通过ε-己内酯（ε-CL）的开环聚合反应,合成氮氧稳定自由基为末端基的聚己内酯（PCL-T）;在其＂介调＂下,进行乙烯基吡咯烷酮（NVP）的氮氧稳定自由基聚合（NMP）,得到结构规整聚己内酯和聚乙烯吡咯烷酮两亲性的嵌段共聚物（PCL-b-PNVP）.通过核磁共振...     

反相悬浮聚合AA-AM-HEMA三元共聚高吸水性树脂的研究

以丙烯酸（AA）、丙烯酰胺（AM）、丙烯酸羟乙酯（HEMA）为单体、N,N'-亚甲基双丙烯酰胺为交联剂、过硫酸铵/亚硫酸氢钠为氧化还原引发剂、Span80/Tween80为复合悬浮分散剂，采用反相悬浮聚合法合成了AA-AM-HEMA三元共聚高吸水性树脂。研究了单体用量、分散剂用量、油水比和粒径等对树脂性能的影响。用TGA和DSC对树脂的保水性和脱水动力学进行了研究，IR分析证实所合成的树脂为丙烯酸-丙烯酰胺-丙烯酸羟乙酯三元共聚物。     

单分散聚苯乙烯微球的制备及影响因素研究

以聚乙烯吡咯烷酮为分散剂，无水乙醇为反应介质，偶氮二异丁腈为引发剂，采用分散聚合工艺，通过优化反应条件，制备出了粒径为5μm单分散（分散系数≤5％）聚苯乙烯微球。所制备的聚苯乙烯微球标准偏差δ＝0．16μm，分散系数ε＝0．02，且具有良好的球形度，表面非常光滑，无破损，无缺损。对影响单分散聚苯乙烯微球的因素进行了研究，结果表明：随着分散稳定剂用量的增加，聚苯乙烯微球的粒径减小；随着单体和引发剂用量的增加，聚苯乙烯微球的粒径增大。分散稳定剂和单体用量是影响聚苯乙烯微球粒径分布的两个主要因素。     

Gels from a semifluorinated n-alkane in fluorinated solvents as a probe for intermolecular interactions

Diblock semifluorinated n-alkanes can form aggregates and gels in fluorinated solvents. We have investigated the thermal behavior of binary mixtures comprising F(CF₂)₈(CH₂)₁₆H and fluorinated solvents. The solvents were perfluorohexane, perfluoroheptane, perfluorooctane, perfluorooctyl bromide, perfluorodecalin, and perfluorotributylamine. The phase diagrams were used to calculate the activity coefficients of the two components and the main excess thermodynamic functions. The solubility and self-assembly behavior of F₈H₁₆ in the fluorinated solvents are related to the different solute–solvent dispersion interactions that depend on the polarizabilities and ionization potentials of the interacting species, and on the structural properties of the solvent.     

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性     

HCOO在Cu(110)、Ag(110)和Au(110)表面的吸附

采用密度泛函理论(DFT)以及广义梯度近似方法(GGA)计算了甲酸根(HCOO)在Cu(110)、Ag(110)和Au(110)表面的吸附. 计算结果表明, 短桥位是最稳定的吸附位置, 计算的几何参数与以前的实验和计算结果吻合. 吸附热顺序为Cu(110)(-116 kJ·mol-1)>Ag(110)(-57 kJ·mol-1)>Au(110)(-27 kJ·mol-1), 与实验上甲酸根的分解温度相一致. 电子态密度分析表明, 吸附热顺序可以用吸附分子与金属d-带之间的Pauli 排斥来关联, 即排斥作用越大, 吸附越弱. 另外还从计算的吸附热数据以及实验上HCOO的分解温度估算了反应CO2+1/2H2→HCOO的活化能, 其大小顺序为Au(110)>Ag(110)>Cu(110).     

Transition metal complexes of the tripodal ligand 4-(2′-pyridylmethyl)-4-azaheptane-1,7-diamine. Crystal structures of [CuLCl]ClO4 and [NiL(MeCN)2](ClO4)2

The tripodal ligand 4-(2′-pyridylmthyl)-4-azaheptane-1,7-diamine has been prepared by reaction of 2-aminemethyl pyridine with acrylonitrile, followed by the reduction of the nitrile groups. Copper(II), nickel(II), zinc(II), cobalt(III) and chromium(III) complexes of the ligand have been prepared and characterized and the crystal structures of the complexes [CuLCl]ClO₄ and [NiL(MeCN)₂](ClO₄)₂ determined. The copper complex is five coordinate with approximate square pyramidal stereochemistry with the apical position occupied by a primary amine donor. The nickel complex is octahedral with the pyridine nitrogen donor lying trans to an acetonitrile ligand.     

SYNTHESIS AND CHARACTERIZATION OF METAL COMPLEXES WITH AMPICILLIN

Abstract

The reaction, in water, of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with sodium ampicillinate at room temperature has allowed isolation of dimers with the following general formula [M(amp)Cl]₂ × nH₂O (n = 1.5?3.2). The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibilities and spectroscopic methods (IR, Raman, EPR and UV-Visible). A dinuclear structure based on octahedrally coordinated metal ions is proposed.     

Magnetism of metal-nitroxide compounds involving bis-chelating imidazole and benzimidazole substituted nitronyl nitroxide free radicals

Coordination compounds based on imidazole and benzimidazole substituted nitronyl nitroxide radicals with transition metal ions and trivalent lanthanide ions are described from the perspective of their magnetic properties.For the transition metal compounds the crystal structures show various metal-nitroxide dimensionalities including mononuclear (0D), one-dimensional (1D) and two-dimensional (2D) complexes. The mononuclear complexes were isolated with most metal ions of the first transition series. One copper(II) complex shows a copper(II)-radical ferromagnetic coupling (J = +75 cm⁻¹) while for the other mononuclear compounds, mainly with manganese(II), the metal-radical interactions are antiferromagnetic. The one-dimensional and two-dimensional complexes are manganese(II) compounds which show canting effects leading to weak ferromagnetism.For the trivalent lanthanide ions [La(III), Gd(III) and Eu(III)], three series of mononuclear complexes were obtained in which the metal center is bound to four, two or one nitroxide radicals depending on the counter ions and ancillary ligands. Unexpectedly, in most gadolinium(III) complexes, the Gd(III)-radical interactions were found to be antiferromagnetic in contradiction with other foundings and previous theoretical models. In support to the magnetic studies, the optical properties of the lantanide complexes have also been investigated and are briefly described.     

具有聚集诱导发光性质的近红外荧光染料

聚集诱导发光(AIE)现象的发现为解决传统有机荧光分子在高浓度和聚集形态下存在的荧光猝灭问题提供了最佳方案,并实现了在光电器件、化学传感、生物成像和靶向治疗等众多领域的广泛应用。随着对AIE发光机理研究的不断深入,AIE分子体系得到了极大的扩展。其中,一类具有给体-受体结构的AIE分子能够显著降低分子能隙,使发光分子波长从可见光区(400~700 nm)延伸到近红外(NIR)区(700~1700 nm)。由于NIR发光分子在生物医学领域中的独特优势,其已成为目前AIE研究的热点。随着对NIR分子设计及应用的不断探索,附加不同功能且发光波长更长的AIE分子也被开发出来了,并实现了对生物体特定组织的NIR荧光成像、光声成像、光动力治疗和光热治疗等。本文总结了近年来具有AIE性能的NIR荧光分子的结构及其在生物医学领域的相关应用。     

Simple,Selective, and Sensitive Spectrophotometric Method for Determination of Trace Amounts of Nickel（Ⅱ）, Copper （Ⅱ）, Cobalt （Ⅱ）, and Iron （Ⅲ） with a Novel Reagent 2-Pyridine Carboxaldehyde Isonicotinyl Hydrazone

A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.     

New Complexes of Ditopic Ligands with “d” and/or “s” Metal Ions

Abstract

The asymmetric compartmental macrocycles containing one N₂O₂ or N₃O₂ Schiff base and one O₂O₃ or O₂O₄ crown-ether like chamber, have been obtained by condensation reaction of the formyl precursors 3,3′-(3-oxapentane-1, 5-diyldioxy) bis (2-hydroxybenzaldehyde) or 3,3′-(3,6-dioxaoctane-1,8-diyldioxy)-bis(2-hydroxybenzaldehyde) with ethyl ethylenediamine (H₂L_A, H₂L_C), 1,5-diamino-3-azamethylpentane(H₂L_B, H₂L_D), also in the presence of metal ions as templating agents. These ditopic ligands, with dissimilar coordination sites, have been designed and used for the selective complexation of “d” and/or “s” metal ions, respectively into the Schiff base and the crown ether chamber. The selectivity of these processes strongly depends on the size and on the donor atom sets of the sites. The possibility to obtain mononuclear M(L)·nH₂O (M = Ni²⁺, Cu²⁺, Co²⁺), Mn(L)(CH₃COO)·nH₂O or Na(L) and hetero-dinuclear MNa(L)(CH₃COO) (M = Ni²⁺, Cu²⁺, Co²⁺) and MnNa(L)(CH₃COO)₂·nH₂O complexes has been successfully tested. The ligands and complexes have been characterized by ir, nmr, mass spectrometry and magnetic susceptibility measurements.

Two of the ligands used for the preparation of the solid samples, i.e., to H₂L_A and H₂L_B, have been employed to study complexation reactions of Co(II) and Na(I) in solution. In order to obtain information on the ligand preorganization effect toward the complex stabilities, a simpler open chain parent compound of H₂L_B (H₂L_E) has been also prepared and studied. FT-IR spectra show that H₂L_A is unable to complex Na⁺ in DMSO while the complexation reactions of Na⁺ by H₂L_B and of Co²⁺ by H₂L_A take place with slow kinetics. Therefore, thermodynamic data have been obtained only for the systems Co²⁺/H₂L_B and Co²⁺/H₂L_E. The thermodynamic parameters obtained for the complexation reactions show that the pre-organization of the donor atoms in H₂L_B does not add a significant contribution to the stabilities of the complexes. Both H₂L_B and H₂L_E form in DMSO 1:1, 1:2 and 1:3 = M:L complexes with very similar stabilities and almost equal enthalpies of formation. Physico-chemical studies suggest besides that the slow reaction of Na⁺ with H₂L_B is probably due to the formation of a 1:1 complex where the metal cation, initially occupying the O₃ cage of the ligand, slowly binds also the oxygens of the phenolic moieties. Spectral and calorimetric data on solutions containing H₂L_B and different Co²⁺: Na⁺ ratios evidence that in DMSO no stable heterodinuclear complexes form when the neutral ligand is considered.     

Synthesis of Some Novel Class of Bis(isoxazoline) and Bis(aziridine) Derivatives

Synthesis of some new bis(isoxazoline) derivatives has been described from terepthaldehyde derived bis(nitrones) using microwave irradiation via 1,3‐dipolar cycloaddition reaction. Bis(isoxazoline) derivatives in turn successfully converted into new bis(aziridine) derivatives via Baldwin rearrangement. Simple reaction methodology, non involvement of catalysts, and good to excellent yields are the important features noticed in this synthesis.