红外光谱的超微量样品 KBr 压片测量技术

为了提高微量KBr压片红外光谱的灵敏度,普遍采用缩小锭片直径的方法,以便使微量样品尽可能多地落在经聚焦后的光束辐照范围内。因此,目前KBr锭片直径最小已达0.5厘米。这样势必导致光能量的过大损失,影响光谱质量。为了克服这一困难,我们改进了通用的均匀KBr压片方法,采用夹心式非均匀KBr压片技术,在KBr锭片直径为4毫米的条件下,把微克量级的样品集中在锭片中心约0.5×4毫米~2的区域内,使之与光源的成象截面的几何大小相匹配,这样,提高了光谱质量和灵敏度,获得了1—5微克样品的红外光谱。     

减少13mm KBr锭片样品用量的简便方法

在红外制样技术中,13mm KBr压模是最常用的。通常对于定性分析,13mm KBr压模需要使用1-1.5mg的样品。如果使用内孔为11×3mm的硬纸框,可将样品量减少至0.3～0.5mg。但是,使用硬纸框制备的KBr锭片往往有几个缺点:1.矩形样品区与纸框的结合部透明度较差,因此会增加光谱的本底吸     

新型光固化环氧丙烯酸酯乳液的制备及其防腐性能研究

将环氧树脂和非离子型表面活性剂在一定温度下与丙烯酸反应合成出改性环氧丙烯酸酯树脂,再利用相反转乳化法制备得到光固化水性环氧乳液。对该反应的原料种类、反应条件、以及乳化工艺进行了优化研究,并对不同条件下得到的乳液进行了综合性能评价。着重考察了环氧树脂的种类以及光引发剂的种类对乳液粒径、清漆膜电化学防腐性能和耐盐雾性能的影响。结果表明:选取环氧树脂E20,光引发剂IRGACURE651,酯化反应温度为105℃,反应时间3h,乳化温度为25℃~30℃,搅拌速度为800r/min时,制得的乳液稳定性和漆膜性能(包括漆膜的力学性能、电化学防腐性能和耐盐雾性能)最佳。     

区熔硅晶片做红外窗口材料

KBr晶体是一种优良的中红外光学材料,其透过率可高达90％以上,为中红外窗口的首选材料。但其吸潮性强、易损坏,用其做为红外分析液体样品的衬底窗片,使用不便。     

多壁碳纳米管对环氧树脂/聚醚酰亚胺体系相分离的影响

通过溶液混合的方法制备了环氧树脂/聚醚酰亚胺(PEI)/多壁碳纳米管(MWCNTs)三元复合物,并使用扫描电镜(SEM)、原位红外分析(FTIR)、流变测试和非等温DSC等手段研究了MWCNTs的存在对体系相分离形貌和固化反应的影响.扫描电镜的结果显示,在固化后的样品中MWCNTs较均匀地分散在两相中.150℃下固化,不含MWCNTs和MWCNTs含量为0.75 pbw的体系相分离形貌呈海岛状结构,而进一步增大MWCNTs含量后相分离形貌呈双连续结构,且相区尺寸随MWCNTs含量的增加而减小.120℃下固化,不含MWCNTs和MWCNTs含量为0.75 pbw的体系相分离形貌呈双连续结构,而进一步增大MWCNTs含量后,体系相分离形貌呈相反转结构.FTIR和DSC的测试结果表明,MWCNTs表面的羟基对环氧树脂的固化反应起到催化作用,使得固化反应速度加快,反应活化能降低.而流变测试的结果表明,随着MWCNTs含量增加,一方面交叉跨越多个相区的碳纳米管使得体系黏度增大,对相分离起到了一定的抑制作用;另一方面使得体系凝胶化时间提前,导致体系相分离形貌被固定在相分离的较早阶段,起到有效调控相分离形貌的作用.     

干燥KBr的简便方法

KBr是一种比较常用的红外透光材料。用KBr晶体加工制作的透光窗片,在红外光谱的5000cm~(-1)到400cm~(-1)范围内完全透明。如果用KBr作为压片的基质,KBr锭片的透光范围可从5000cm~(-1)延伸到300cm~(-1),因此在红外光谱分析中,KBr是最常用的一种压片基质。KBr易溶于水,它比KCl更容易潮     

活性酯固化邻甲酚环氧树脂反应机理的研究

采用交叉反应研究在促进剂2-甲基咪唑存在下活性酯固化邻甲酚环氧树脂的反 应机理，用傅立叶转换红外（FTIR）原位测量技术，NMR，气-质联用（GC-MS）等 手段研究了模型化合物的反应动力学，并提出了其反应机理。结果表明，在促进剂 2-甲基咪唑存在下活性酯固化邻甲酚环氧树脂的反应是通过分子内机理进行的。     

基于次氯酸钙的高铁酸钾制备与表征

为提高化学氧化法制备高铁酸钾的安全性,以次氯酸钙和碳酸钾反应制备碱性饱和次氯酸钾,继而氧化九水硝酸铁制备高铁酸钾。对制备条件进行了优化,结果表明次氯酸钾浓度1.15mol/L,反应时间60min,重结晶碱浓度15.48mol/L,正戊烷和无水乙醇交替洗涤除杂条件下所制备的高铁酸钾纯度较高。采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)以及紫外-可见吸收光度法对样品进行定性分析,证实所制备样品为高铁酸钾。采用邻菲罗呤分光光度法定量测定样品纯度,高铁酸钾含量大于97%。     

聚丙烯酸辅助水热合成CdS纳米片

利用聚丙烯酸(PAA)和硫代乙酰胺(TAA)合成大分子硫源,采用水热的方法在180℃下制备立方相CdS纳米片,纳米片平均大小在100nm.用X射线衍射仪器(XRD),透射电子显微镜(TEM),红外吸收光谱(FTIR)和紫外吸收光谱(UV-Vis)对CdS纳米片进行了形貌和性能表征,并分析了CdS纳米片形成的可能机理.此外,反应的溶剂对CdS纳米材料的形貌有重要的影响.     

新型环氧树脂基液晶光定向层材料的合成与性能研究

经双酚A型环氧树脂与苯胺缩聚反应,制备含有羟基的先驱聚合物EP-AN,通过EP-AN上羟基与肉桂酰氯的酯化反应,制备了侧链带有肉桂酸酯基团的光敏聚合物EP-AN-CI.用核磁共振(1HNMR)、傅里叶红外光谱(FTIR)和热分析等手段确定了上述聚合物的结构与性能.用FTIR等方法表征了EP-AN-CI的光交联反应.经线性偏振光聚合技术(LPP)处理聚合物EP-AN-CI膜制备成液晶定向层,通过装配液晶盒和偏光显微镜观察表明,所制备的定向层具有很好的定向能力,该聚合物是一类具有潜在应用价值的新型液晶光定向层材料.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。