Extended UNIQUAC model for thermodynamic modeling of CO2 absorption in aqueous alkanolamine solutions

The extended UNIQUAC model [K. Thomsen, P. Rasmussen, Chem. Eng. Sci. 54 (1999) 1787–1802] was applied to the thermodynamic representation of carbon dioxide absorption in aqueous monoethanolamine (MEA), methyldiethanolamine (MDEA) and varied strength mixtures of the two alkanolamines (MEA–MDEA). For these systems, altogether 13 interaction model parameters are adjusted. Out of these parameters, 11 are temperature dependent.     

Geometry,Electronic Structure,and Related Properties of Dye Sensitizer： 3,4-bis[1- （carboxymethyl）-3-indolyl]- 1 H-pyrrole-2,5-dione

The geometry, electronic structure, polarizability and hyperpolarizability of dye sensitizer 3,4-bis[1-（carboxymethyl）-3-indolyl]-1H-pyrrole-2,5-dione （BIMCOOH） were studied using density functional theory （DFT） with hybrid functional B3LYP, and the electronic absorption spectra were investigated using semi-empirical quantum chemical method ZINDO-1 and time-dependent DFT （TDDFT）. The results of natural bond orbital suggest that the natural charges of the dione, indole, and acetic groups are about 0.15e, -0.29e, and 0.44e, respectively. The calculated isotropic polarizability, polarizability anisotropy invariant and hyperpolarizability are 305.4, 188.3, and 1155.4 a.u., respectively. The electronic absorption spectral features in visible and near-UV region were assigned to the π→π^＊ transition due to the qualitative agreement between the experiment and the TDDFT calculations, and the transitions of the excited states 9-11 related to photoinduced intramolecular charge transfer processes. The analysis of electronic structure and UV-Vis absorption indicates that the indole groups primarily contributed sensitization of photo-to-currency conversion processes, and the interracial electron transfer between semiconductor TiO2 electrode and dye sensitizer BIMCOOH are electron injection processes from excited states of the dyes to the semiconductor conduction band.     

超细镍粉复合材料的微波电磁特性研究

以蒸馏水为溶剂,利用快捷、温和的液相还原法制备超细镍粉,将得到的超细镍粉作为填料制备了复合材料,考察了复合材料的电磁屏蔽和吸波性能．结果表明,超细镍粉质量分数为80％的树脂基复合材料在130MHz～1．5GHz测试频段范围内的电磁屏蔽性能高于45dB;而厚度为2mm的超细镍粉／石蜡复合材料在7GHz附近的反射率可达-27dB．     

Synthesis of a “molecular rope curtain”: Preparation and characterization of a sliding graft copolymer with grafted poly(ethylene glycol) side chains by the “grafting onto” strategy

A sliding graft copolymer (SGC) with poly(ethylene glycol) (PEG) side chains was prepared by ester formation between terminal carboxyl groups of oxidized PEG methyl ether with molecular weight of 2000 (mPEG2000‐COOH) and hydroxyl groups of a polyrotaxane consisting of PEG and cyclodextrins (CDs). Formation of the SGC structure was confirmed by ¹H NMR, attenuated total reflectance Fourier‐transformed infrared, and gel permeation chromatography. The SGC was soluble in good solvents of PEG and insoluble in poor solvents of PEG. Estimation of the number of grafted mPEG chains suggested a “rope‐curtain” like structure, in which an mPEG chain is connected to each CD ring. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Spectrometry: Speciation of Parts PER Billion of Metal Ions Using Silica and C18-Bonded Silica Columns and Graphite Furnace Atomic Absorption Spectrometry

Abstract

It is demonstrated that silica gel columns will quantitatively adsorb free Cu²⁺ and Pb²⁺ ions at pH > 8. These are eluted with 0.1 M HNO₃ but not with methanol. Negatively charged EDTA chelates are not adsorbed. Neutral APDC chelates are partially adsorbed on silica columns, but are quantitatively adsorbed on C18-bonded columns, and are eluted with methanol. The metal ions are partially adsorbed on C18-bonded columns, due to residual silanol groups. A microcolumn (1 mm i.d., 5 cm length) manifold system is described for automatic delivery of eluant (0.12 ml) to a heated atomic absorption graphite atomizer, using either methanol or 0.1 M HNO₃ in methanol eluant, allowing speciation and measurement of parts per billion of metals. These studies demonstrate that by using a mixed column or sequential columns of silica gel and C18-bonded silica, cationic and neutral metal species could be adsorbed, followed by sequential elution and measurement using methanol and then 0.1 M HNO. Negatively charged species could be measured directly in the sample eluant or obtained by difference from a total metal measurement.     

SYNTHESIS,CHARACTERIZATION AND CRYSTAL STRUCTURE OF A COMPLEX OF EUROPIUM PERCHLORATE WITH METHYLENE BIS(DIPHENYLPHOSPHINE OXIDE)

Abstract

A complex of europium perchlorate with methylene bis(diphenylphosphine oxide) (HMPPO), [Eu(HMPPO)₄](ClO₄)₃·2H₂O has been synthesized and characterized by X-ray crystallography, infrared spectroscopy and thermal analysis. The X-ray structure of the complex shows Eu(III) is coordinated by eight oxygen atoms from four HMPPO ligands, forming a distorted square antiprism coordination geometry. The complex crystallizes in space group P-1 with cell parameters a = 15.807(3), b = 17.868(4), c = 20.656(4) Å, α = 86.85(3)°, β = 82.33(3)°, γ = 66.75(3)°. The final R_l and R_w are 0.0803 and 0.1994, respectively, for 9540 observed reflections [I > 2[sgrave](I)]. Its luminescent properties have also been studied.     

食品中偶氮染料丽春红2R的鉴定

应用常规分析方法和红外光谱,对掺入食品中偶氮染料丽春红2R进行鉴定,对偶氮染料晚霞黄和丽春红3R进行分析比较。同时运用紫外吸收光谱分析七种可食用合成色素。     

氧化石墨烯基异丙隆分子印迹聚合物的制备及其吸附性能研究

以氧化石墨烯为载体,异丙隆为模板分子,采用表面印迹技术制备了分子印迹聚合物。采用透射电子显微镜、拉曼光谱和热重分析仪对该分子印迹聚合物的结构进行了表征,并通过动态平衡结合法研究了该分子印迹聚合物的吸附能力。结果表明:准二级动力学模型很好地拟合了吸附动力学,相关系数(R2)为0.999 7;与非分子印迹聚合物相比,制备的印迹材料表现出高吸附效率和快速的吸附动力学;选择性吸附试验表明该分子印迹聚合物对异丙隆具有选择性和特异性吸附。     

缝管原子捕集原子吸收光谱法测定维生素B12

本文研究了Ａｌ２Ｏ２涂层的开缝石英管原子捕集法测定ＣＯ的条件并通过测ＣＯ间接测定维生素Ｂ（１２）。结果表明，在优化条件下Ｃｏ的特征浓度为８×１０（－３）μｇ·ｍＬ（－１），比常规火焰原子吸收法的灵敏度提高８倍。采用本法测定腺苷辅酶维生素Ｂ（１２）中ＶＢ（１２）的含量，相对标准偏差１．１％，加标回收率９８．２～１００．４％。     

On the chemistry of pyrrole pigments,XCIII: 1,2-bis-(dipyrrinon-9-ylidene)-ethane — a novelb-homoverdin chromophore

Summary Condensation of a 9-unsubstituted dipyrrinone with glyoxal in dichloromethane yielded a red pigment. It could be identified as 1,2-bis-(dipyrrinon-9-ylidene)-ethane which is an example of the hitherto unknown dehydro-b-homo-verdins. In addition, the corresponding mesobiliverdin-XIII could be isolated from the reaction mixture. The mechanistic aspects of this reaction are discussed. Absorption spectra, protonation equilibria, and complexation of the title compound with transition metal ions were investigated.

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Zur Chemie von Pyrrolpigmenten, 93. Mitt.: 1,2-bis-(Dipyrrinon-9-yliden)-ethan — ein neuerb-Homoverdin Chromophor

Zusammenfassung Kondensation eines 9-unsubstituierten Dipyrrinons mit Glyoxal in Dichlormethan unter saurer Katalyse ergab ein rotes Pigment. Dieses konnte als 1,2-bis-(Dipyrrinon-9-yliden)-ethan identifiziert werden, welches ein Beispiel für die bislang nicht bekannten Dehydro-b-homoverdine darstellt. Darüber hinaus konnte dabei auch aus der Reaktionsmischung das entsprechende Mesobiliverdin-XIII isoliert werden. Die mechanistischen Aspekte der Bildungsreaktion werden diskutiert. Absorptionsspektren, Protonierungsgleichgewichte und die Komplexierung mit Übergangsmetallionen wurden untersucht.