3-芳甲酰基香豆素类化合物光引发聚合的研究

<正> 近年来,3-芳甲酰基香豆素类化合物,作为有效的用于高分子光引发交联的光敏剂和光共引发剂已受到重视,Williams等曾对这类化合物在高分子薄膜中的聚合能力进行了研究,认为其作为光敏剂效果甚佳。本文研究了光敏剂(scn.1)-三乙胺(TEA)体系引发甲基丙烯酸甲酯(MMA)的光聚合,通过与二苯酮(BP)-TEA体系比较,指出了前者具有更高的引发效率,并从光引发聚合体系中光敏剂的激发态性质揭示了这一过程     

Synthesis of morphological ZnO particles by a facile solution-based chemical method

In this study, a facile solution-based chemical method has been developed to produce ZnO particles in the presence of triethanolamine (TEA) and NaOH. In this novel method, TEA acted as complexing reagents, and NaOH contributed to the transformation of ZnO precursor (Zn–TEA complex) into ZnO particles. The core of this new strategy is to transform Zn–TEA complex into morphological ZnO particles directly by a facile solution method. The results from transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) analysis revealed that the morphologies of the as-prepared ZnO samples evolved from slices to quasi-spheres by increasing the amount of TEA. X-ray diffraction (XRD), Raman and room-temperature photoluminescence (PL) tests showed that these ZnO samples had wurtzite structures. A reasonable mechanism for the transformation of Zn–TEA complex into morphological ZnO particles was supplied.     

H2和I2反应的赝势法量子化学研究

用赝势价轨道从头算方法并采用双组态行列式波函数, 找出了H_2与两个碘原子反应形成的直线型过渡态的几何构型。根据这个构型, 利用CIPSI程序进行了微扰CI计算, 得到了反应活化能的近似值。根据所得到的结果对H_2与I_2反应的机理进行了探讨, 支持了三分子反应的观点。     

Rheological properties and microstructures of Carbopol gel network system

Carbopol gel systems have been studied using steady, oscillatory rheology, and cryoscanning electron microscopy (cryo-SEM) analysis in order to elucidate the nature of the different microstructures of the gel in relation to polymer concentration as well as triethanolamine (TEA) content. The effect of changing the concentration of Carbopol (0.1–4 wt%) for 0, 1, and 10 wt% TEA has been investigated. Cryo-SEM revealed that honeycomb structures were observed in the gel system depending on the amount of TEA and Carbopol while the irregular fibrous three dimensional gel network systems were seen at the lower level of polymer content even in the high concentration of TEA. In addition to that, as the amount of polymer was increased, strings of fibrous network became thicker and of honeycomb-like structure. Shape of storage modulus-shear stress curve in the dynamical rheometric study was significantly changed as a result of variation in the microstructures while frequency sweep curve and yield values obtained from the model fitting in the steady rheological measurements couldn't reflect the structural difference of Carbopol gels. Two distinct relaxation phenomena were appeared with increase in polymer concentration as well as TEA concentration. Temperature dependence of the stress sweep experiment was measured and shown that the effect of temperature (1–80 °C) on the shape of the curve was the similar trend with that of TEA and polymer concentrations, although the temperature dependency on the increment was much weaker than TEA concentration.     

Trace analysis of volatile N-nitroso compounds by combined gas chromatography and thermal energy analysis.

Thermal energy analysis (TEA) has been combined with gas chromatography (GC). The new GC-TEA technique is highly specific to compounds which contain heat labile nitrosyl groups. Because of the specificity of the technique, full use may be made of the TEA sensitivity. Analysis by direct injection of solutions containing less than 1 ng/ml N-nitroso compound is demonstrated.     

Ba+Cl2, Br2化学发光反应动力学研究——电子激发态BaCl2*的生成机理

本文在束-气化学反应装置中, 研究了Ba+Cl_2(Br_2)化学发光反应, 观测了BaCl_2~*(BaBr_2~*)连续发射和Ba(~1P→~1S)辐射强度与反应物浓度的关系, 并用OMA观测了BaCl_2~*(BaBr_2~*)的发光强度的空间分布。实验结果否定了生成BaCl_2~*的单次碰撞的各种设想, 通过形成高振动激发的电子基态中间产物的二步反应机理, 成功地解释了实验观察的各项结果, 证明这个机理是可信的。     

模板剂四乙基氢氧化铵的用量对合成的β沸石结构及脱胺的影响

研究四乙基氢氧化铵（TEA-OH）模板剂用量对合成的β沸石的结构及脱胺行为的影响。合成β沸石的模板剂的较佳用量(TEA+/Al)为2.10～1.68,合成的β沸石的相对结晶度均大于84%;β沸石中的铝含量(Al/Al+Si)及骨架铝含量(TdAl/TdAl+OhAl)随晶化混合液的TEA+/Al而变,存在最佳TEA+/Al点为1.9,此时合成的β沸石非骨架铝量最少,结构硅铝比最高;含TEA的β沸石脱胺过程为Hofmann降解反应,TGA测定的失重量、DSC测定的吸热量与β沸石中TEA含量密切相关.     

Stoichiometric formation of methyl methacrylate oligomer by triethylaluminum in the presence of azobisisobutyronitrile

The yield of methyl methacrylate (MMA) polymerization as a function of triethylaluminum (TEA) concentration for a constant azobisisobutyronitrile (AIBN) concentration at 50°C has been measured. The polymerization yield does not differ markedly from that with AIBN alone as long as the initial TEA concentration is held smaller than four times the initial AIBN concentration. A sudden decrease in yield and molecular weight is observed at TEA/AIBN concentration ratios between 4 and 5. A plot of M?_w^?1 vs. TEA gives a rate-transfer constant of 89 1./mole-sec. If the reaction mixture is vacuum-evaporated with a previous addition of water, instead of precipitating the polymer, the formation of a considerable amount of MMA oligomer is detected for TEA/AIBN concentration ratios larger than 4. On the average, each TEA molecule in excess of four times the initial amount of AIBN yields one oligomer molecule. The data are consistent with a radical polymerization mechanism for the high molecular weight polymer and with a nonradical one for the oligomer formation.     

Influence of Hydrogen Bonding and Polarity on the Spectral Properties of 4-Aminophthalimide Clusters Formed with Triethylamine and Dimethyl Sulfoxide in Solution

The time-dependent density functional theory (TDDFT) method has been carried out to study the influences of hydrogen bonding and solvent polarity on the spectral properties of 4-aminophthalimide (4AP) clusters formed with hydrogen-accepting solvents triethylamine (TEA) and dimethyl sulfoxide (DMSO). The ground- and S₁-state geometry structure optimizations, hydrogen bond energies, absorption and emission spectra for both the 4AP monomer and its two triply hydrogen-bonded clusters 4AP + (TEA)₃ and 4AP + (DMSO)₃ have been calculated using DFT and TDDFT methods respectively with the hybrid exchange correlation functional PBE1PBE and split-valence basis set 6-311++G(d,p). It has been demonstrated that the two hydrogen bonds I and II formed with the amine group of 4AP are significantly strengthened while the hydrogen bond III formed with the imide group is slightly weakened due to the intramolecular charge transfer from the amine group to the two carbonyl groups of the 4AP molecule upon photoexcitation. In addition, the hydrogen bonds formed by 4AP with DMSO are stronger than those formed with TEA, which together with its strong polarity, should be the main reasons for the more redshifts of both the absorption and the fluorescence spectra of 4AP in solvent DMSO than those in TEA.     

Coupled transport of Ag(I) ions through triethanolamine–cyclohexanone-based supported liquid membranes

Facilitated transport of silver(I) ions in acidic medium, across a supported liquid membrane (SLM) by using triethanolamine (TEA) as carrier, dissolved in cyclohexanone, has been investigated. The parameters studied are HNO₃ concentration variation in the feed, pH of the feed solution, carrier concentration in the membrane phase, silver(I) ions concentration in the feed phase and KCN concentration in the stripping phase. Increase in H⁺ concentration by increasing HNO₃ concentration from 0.5 to 1 M results into an increase in silver ions flux but a decrease in flux has been found beyond 1 M HNO₃ concentration in the feed, providing a maximum flux of 3.21 × 10⁻⁷ mol/m² s at 1 M HNO₃. Increase in TEA concentration inside the membrane enhances flux with its maximum value at 2.25 M TEA. Further increase in the concentration of TEA leads to a decreased rate of transport due to the increase in viscosity of membrane liquid. The optimum conditions for Ag(I) ions transport are 1 M HNO₃ (feed), 2.25 M TEA (membrane) and 1.5 M KCN in the stripping phase. It has been observed that Ag(I) flux across the membrane tends to increase with increase in Ag(I) ions concentration in the feed phase. Applying the studied conditions to silver plating waste solutions, Ag ions have been removed up to 99% in a time interval of 5 h.     

模板剂对SAPO─34分子筛性能的影响

分别以三乙胺、四乙基氢氧化铵以及二者的混合物为模板剂，采用水热法合成了三种ＳＡＰＯ－３４分子筛样品。用化学分析、ＸＲＤ、ＴＰＤ和ＩＲ方法研究了不同模板剂对ＳＡＰＯ－３４分子筛性能的影响。实验结果表明，四乙基氢氧化铵有利于硅进入分子筛骨架；三乙胺有利于生成较多的强酸中心；将三乙胺与四乙基氢氧化铵联用，能有效地调变所合成的ＳＡＰＯ－３４的酸中心分布，使其对甲醇转化制低碳烯烃具有较高的选择性。     

The Anomalous Triplet Exciplex Emission of 4-phenylbenzophenones with Amines

Structured phosophorescence with 20μs life time[480nm, 510nm (max),550nm] from 4-phenyl-benzophenone (4-PBP) was quenched by trieyhylamine (TEA) in benzene. An Anomalous exciplex emission with strutureless peaking at 647nm and 30μs life time. A quenching mechanism has been shown to involve a mixed (π,π^*) and (n,π^*) triplet of 4-PBP to form an exciplex with the grond state of TEA.     

Simultaneous determination of nitrite and nitrate by normal phase ion-pair liquid chromatography

Normal phase ion-pair high performance liquid chromatography has been used for simultaneous separation of nitrite and nitrate using tetraethylammonium (TEA)(+) as ion-pairing reagent. The concentration effect of (TEA)(+), buffer salt and pH of the eluent on separation is investigated. The UV detector response at various wavelengths has been optimized. The performance of the proposed method is compared with ion chromatography for quantification of the anions in potable water, wastewater and in food samples, such as spinach and lettuce.     

两亲两嵌段共聚物PS-b-PAA合成及其在溶液中的形态和纳米聚集结构形成

采用了ATRP方法合成了由苯乙烯及丙烯酸组成的两亲两嵌段共聚物PS b PAA ,对它们的结构组成进行了详细表征 .用荧光探针方法以二甲基氨基黄酮类化合物为探针测定了这类两亲高分子化合物的类胶束形成时的临界浓度 .并对它们所形成的特殊胶束形态通过电镜观察 ,清楚的看到在纳米线条形成过程中由纳米小球向纳米线的转变     

Synthesis,Characterization and Spectral Studies of Triethanolamine Complexes of Metal Saccharinates. Crystal Structures of [Co(TEA)2](SAC)2 AND [Cu2(μ-TEA)2(SAC)2]·2(CH3OH)

The novel transition metal saccharinate complexes of triethanolamine (TEA) have been synthesized and characterized by elemental analyses, magnetic moments, UV-Vis and IR spectra. Mn(II), Co(II), Ni(II), Zn(II), Cd(II) and Hg(II) form mononuclear complexes of [M(TEA)₂](SAC)₂, where SAC is the saccharinate ion, while the Cu(II) complex is dimeric. The TEA ligand acts as a tridentate N,O,O'-donor ligand and one ethanol group is not involved in coordination. The SAC ion does not coordinate to the metal ions and is present as the counter-ion in the Mn(II), Co(II), Ni(II), Zn(II), Cd(II) and Hg(II) complexes, but coordinates to the Cu(II) ion as a monodentate ligand. The crystal structures of the [Co(TEA)₂](SAC)₂ and [Cu₂(μ-TEA)₂(SAC)₂]·2(CH₃OH) complexes were determined by single crystal x-ray diffraction. The Co(II) ion has a distorted octahedral coordination by two TEA ligands. The Cu(II) complex crystallizes as a dimethanol solvate and has doubly alkoxo-bridged centrosymmetric dimeric molecules involving two tridentate triethanolaminate (deprotonated TEA) and two monodentate SAC ligands. The geometry of each Cu(II) ion is a distorted square pyramid. Both crystal structures are stabilized by hydrogen bonds to form a three-dimensional network.     

Buffer effect on the kinetics of ornithine carbamyl transferase by HPLC

A kinetic study of ornithine carbamyl transferase (OCT) from Streptococcus faecalis has been carried out, employing a new HPLC method based on the direct determination of citrulline. A different kinetic pattern was observed in tris(hydroxymethyl)-aminomethane (TRIS) and triethanolamine (TEA) buffers: a ping-pong or an ordered sequential mechanism are suggested, respectively. The inhibition of Tris buffer on OCT reaction has also been demonstrated. The inhibition of Tris buffer on OCT reaction has also been demonstrated.     

Determination of lead and cadmium in titanium dioxide by differential pulse anodic stripping voltammetry

A procedure for the simultaneous determination of lead and cadmium in TiO(2) by differential pulse anodic stripping voltammetry (ASV) has been developed. The key feature of the method is the use of triethanolamine (TEA) to remove titanium interference: TiO(2) undergoes acidic digestion with HF/H(2)SO(4) at atmospheric pressure, TEA is added to the HCl solution of the residue and the solution is analysed using a standard ASV instrumentation, equipped with a hanging mercury drop electrode. The calibration curves for both lead and cadmium are linear up to 50 mugl(-1) of solution, and the detection limits are 1 mugl(-1), corresponding to 1 mugg(-1) of TiO(2). Method reliability was tested by comparing the results with those given by electrothermal atomic absorption spectroscopy. The method has been successfully applied for determination of both contaminants in powdered titanium dioxide (raw materials) and in titanium dioxide-containing cosmetics (sunscreen products).     

Salting coefficient of triethanolamine in major seawater salts

Activity coefficient of triethanolamine (TEA) in major seawater salts (NaCl, KCl, CaCl₂ and MgCl₂) has been determinated using the distribution method. It increases slowly in KCl, remains almost constant in NaCl and decreases in the other salts. Pitzer model has been used to fit the experimental data and the corresponding interaction parameters have been determinated.     

Synthesis of bicyclo[3.2.1]octanones via ketyl radical promoted rearrangements under reductive PET conditions

Photoinduced electron transfer (PET) reactions from triethylamine (TEA) to ketones have been utilized for a clean and efficient route to bicyclo[3.2.1]octanones. A one-pot conversion of bicyclo[2.2.2]octenones to such molecules has been described. MeOH as well as acetonitrile/LiClO₄ combinations have been found to be the most effective solvents for these reactions.     

Bacterial cellulose/triethanolamine based ion-conducting membranes

New bacterial cellulose (BC)–triethanolamine (TEA) ion-conducting membranes have been prepared and characterized. The samples were obtained by soaking BC membranes in triethanolamine aqueous solutions and drying. The scanning electron microscopy pictures revealed that the incorporation of TEA in BC membranes covers the cellulose microfibrils. Raman spectra exhibited BC and TEA characteristic group frequencies and thermal analysis evidenced an influence of TEA content on the sample thermal stability. The ion-conductivity as a function of the temperature showed an Arrhenius behavior increasing from 1.8 × 10^?5 S/cm at room temperature to 7.0 × 10^?4 S/cm at 80 °C for the BC–TEA 1 M sample.