基于纳米Ag粒子的表面等离子体共振光谱测定CN-的研究

利用UV-辐照光化学还原法制备了平均直径为20 nm的黄色胶体银溶液,银粒子的表面等离子体共振(SPR)光谱的最大吸收波长位于399 nm处,摩尔吸光系数为1.3×104 L·mol-1·cm-1.利用Ag粒子与CN-反应的动力学特性,研究了SPR光谱的λMAX吸光与CN-浓度的关系及其影响因素,拟定了检测环境水样中隐色、有毒CN-离子的方法.标准工作曲线的线性相关系数0.9995,测定下限0.05 μg/mL, 相对标准偏差RSD(%)≤6.1 (n=5).对Ag粒子与CN-反应的机理进行了探讨.     

在阴离子表面活性剂存在下以2-(5'-氯-2'-吡啶偶氮)-5-二甲氨基苯胺分光光度测定银

本文提出了一个简便、灵敏而有选择性的测定银的分光光度法.方法基于银(I)在阴离子表面活性剂十二烷基硫酸钠存在下与2-(5'-氯-2'-吡啶偶氮)-5-二甲氨基苯胺(简称5-Cl-PADMA,1)的颜色反应.银络合物的吸收峰位于500nm,在530nm以显色剂参比摩尔吸光系数6.7×10~4.在pH6～10.5之间吸光值恒定.银浓度在0～1.2ppm时服从Beer定律.用等摩尔连续变化法和摩尔比例法测得络合物中Ag(I)与5-Cl-PADMA的比例为1∶2.在掩蔽剂柠檬酸盐和Ca-CyDTA存在下,该反应对银的测定是选择性的.方法已用于铀和铝试样中银的测定.     

1-偶氮苯-3-(5-氰基-2-吡啶)-三氮烯对银的显色反应及研究

合成了1-偶氮苯-3-(5-氰基-2-吡啶)-三氮烯(ABCPDT),并研究了AB-CPDT与银的显色反应。在Na2B4O7-NaOH缓冲溶液(pH 10.0)介质中,Triton X-100存在下试剂与Ag生成络合物(1∶1)。络合物在550 nm处有最大吸收峰,络合物的表观摩尔吸光系数为1.65×105L.mol-1.cm-1,Ag质量浓度在0~0.48μg/mL范围内符合比耳定律。方法已用于回收定影液中银的测定。     

牛血清蛋白与6,6＇-(3H-2.1-苯并(噁)硫醇-3-叉)二百里酚作用研究

应用UV-Vis光谱法,研究了在pH=1.61的酸性缓冲溶液中,牛血清蛋白(BSA)与6,6＇-(3H-2.1-苯并噁硫醇-3-叉)二百里酚(TB)的相互作用.测得生成复合物的最大吸收峰为440nm,与试剂相比蓝移105nm.微环境的影响使BSA-TB复合物的最大吸收波长之间红移约30nm.应用平衡透析法、摩尔比法和双波长法进行测定,结果表明,表观摩尔吸光系数∈B=1.40×104L·mol-1·cm-1,平均结合数n=7,表观结合平衡常数K=2.59×106.研究发现,该反应基本符合Scatchard模型,认为是BSA与TB之间以静电引力和疏水力综合作用的结果.     

Ag(Ⅰ)-phen-TPPS_4水溶液体系中显色反应的研究

本文提出了在碱性介质中,基于Ag(I)-phen-TPPS_4配合物的生成而建立高灵敏度测定Ag(I)的分光光度法。配合物的最大吸收波长为438nm,摩尔吸光系数为136×10~5L.mol~(-1).cm~(-1)。Ag(I)的浓度在0～0.4μg/mL范围内符合比尔定律。Ag(I)的最低检出限为8.8ng/mL。配合物的组成为Ag(I):phen:TPPS_4=1:2:1。方法简便、快速,应用于生产感光乳胶的废水中微量银的测定,获得较满意的结果。     

寡聚芴纳米粒子的制备、表征与细胞成像应用

利用Suzuki偶联反应合成了疏水性寡聚芴分子OF, 并对其在氯仿溶液中的紫外吸收和荧光光谱进行了表征, 表明其具有较大的摩尔吸光系数(1.08×10⁵ mol^-1·L·cm^-1)和高荧光量子产率(96%). OF分子分散到水中可形成纳米粒子, 动态光散射实验表明其粒径大小约为230 nm. 该纳米粒子在水相中仍保持了较大的摩尔吸光系数以及高的荧光量子产率. 我们利用MTT的方法对OF纳米粒子对人肺癌A549细胞的毒性进行了测试, 结果表明其具有低的细胞毒性, 因此可以用于细胞成像. 共聚焦激光扫描显微镜成像结果显示OF纳米粒子主要分布在细胞质中, 特别是在近核区域周围. 与溶酶体染料Lyso Tracker Red共定位结果表明OF纳米粒子主要存在于溶酶体中, 因此可以用于对溶酶体的特异性荧光成像.     

催化动力学光度法测定微量银

依据在H2SO4介质中,Ag+对(NH4)2S2O8氧化Mn2+的强烈催化作用,建立了测量微量Ag+的新动力学光度法。方法的线性范围为0.05~2.0μg/mL,检出限为1.5×10-5mg/mL,表观摩尔吸光系数为7.1×104L.moL-1.cm-1。测定了反应的动力学参数。用本法测定了矿样和废水样中的银。     

具有SPR效应的Ag/Ag2MoO4材料在可见光区的光催化性能研究

作为一类新兴的光催化材料,钼酸盐纳米材料具有高表面能、多活性位点和高选择性等优点,在可见光催化降解污染物方面有着重要应用,近年来受到广泛关注.作为钼酸盐家族重要的一员,钼酸银在杀菌、表面增强拉曼光谱、气敏材料等方面均有重要应用,但其光催化性能却鲜见报道.这是由于它的光谱响应范围窄和广生载流子分离效率低所致.虽然近来有少量基于钼酸银的复合材料的光催化研究,但催化效果不佳.众所周知,作为自由电子体系,诸多金属纳米粒子,如贵金属、碱金属等,存在表面等离子体共振效应(SPR),使得贵金属,特别是Ag,Au等纳米粒子在可见区域有较强的吸收.利用这一特性,Awazu等将Ag纳米颗粒沉积在TiO2表面,创造性地将SPR应用于光催化反应,开发出在可见光谱区具有宽光谱吸收特征的Ag/TiO2.随后陆续合成出基于SPR效应的Ag@AgCl,Ag/Ag3PO4材料均具有良好的光催化性能.基于此,本文在十二烷基硫酸钠(SDS)的存在下,采用水热法一步合成了具有SPR效应的Ag/Ag2MoO4可见光催化材料,并利用X射线粉末衍射(XRD)、紫外可见漫反射(DRS)、X射线光电子能谱(XPS)和扫描电子显微镜(SEM)等技术对材料进行了表征.系统地探讨了体系pH值、反应时间、表面活性剂用量对产物的晶相和微观形貌等的影响.此外,还利用罗丹明B降解实验考察了上述合成条件对材料可见光催化活性的影响,并通过捕获剂实验深入地研究了起催化作用的活性物种.XRD结果表明,体系的pH值对材料的晶型有极大影响,随着pH由酸性变至中性、碱性,最终得到的钼酸银也由Ag2Mo2O7过渡到Ag2MoO4.SEM图显示在最优条件(pH为7,加入0.5 g SDS,160oC下水热14 h)下制得的钼酸银为八面体的Ag2MoO4,且其表面均匀地分布着Ag纳米颗粒,与XPS图谱结果一致.另外表面活性剂SDS的用量对所合成材料的形貌影响很大.本文可一步得到以八面体Ag2MoO4为主的Ag/Ag2MoO4复合材料,是因为SDS的疏水长链可以诱导Ag2MoO4的各向异性生长.DRS结果表明,Ag2MoO4八面体上Ag颗粒的引入使其在可见光区的吸收明显加强,因而它在可见光下催化降解罗丹明B降解反应活性增加.捕获剂实验结果表明,起决定性作用的活性物种是光生空穴,另外?OH也起了一定作用.     

非水溶性meso-四苯基卟啉与银显色反应的研究

研究了在混合表现活性剂TritonX 100与CTMAB共同存在下,非水溶性meso 四苯基卟啉与银的显色反应。利用该反应建立了高灵敏测定银的光度分析法,用于显影液废水中银的测定,其结果与ICP AES法和AAS法一致。银与TPP形成1∶1的配合物,其最大吸收波长和表观摩尔吸光系数分别为425nm和2.15×105L·mol-1·cm-1,银含量在0.04～4.0μg/10ml范围内服从比耳定律。     

银纳米粒子表面等离子共振吸收-分光光度法测定废水中的邻苯三酚

基于改良银镜反应,利用银纳米粒子的表面等离子共振吸收提出了测定废水中邻苯三酚的分光光度法。室温条件下,在氢氧化钠和氨水混合溶液的碱性环境中,以吐温-20作为分散剂,邻苯三酚作为还原剂,还原银氨溶液,反应生成银纳米粒子,溶液由无色变为亮黄色,并在410nm处产生银纳米粒子表面等离子共振吸收峰。溶液的吸光度与邻苯三酚的浓度在3.96×10-7~2.38×10~(-5) mol·L~(-1)范围内呈线性关系,检出限(3σ)为2.97×10-7 mol·L~(-1),摩尔吸光率为5.483×104L·mol~(-1)·cm~(-1)。该方法应用于工业废水中邻苯三酚的测定,测定值与普通分光光度法的测定结果一致,相对标准偏差(n=5)小于5.0%,加标回收率在95.4%~104%之间。     

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.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

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^-。     

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.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。