以氨水做碱源胶态晶种导向法合成小晶粒TS-1分子筛

TS-1分子筛具有MFI拓扑结构,因其独特的择形选择性和优异的催化氧化能力而广受关注.最早报道的TS-1合成方法采用大量四丙基氢氧化铵(TPAOH)作为有机结构导向剂, TPAOH价格昂贵,制约着TS-1分子筛大规模应用.开发廉价、环境友好的合成工艺是TS-1分子筛合成领域的重要课题.以价格相对较低的四丙基溴化铵(TPABr)代替TPAOH做有机结构导向剂,以氨水为碱源可合成TS-1分子筛,但产物晶粒尺寸远远大于以TPAOH做模板的合成结果,影响TS-1分子筛的传质和催化性能.因此,人们对该法进行了改进,选用有机胺作为碱源, TPABr为结构导向剂合成TS-1分子筛,但始终未能将其晶粒尺寸降至1μm以下.在合成体系中引入预先合成的TS-1分子筛或TS-1胶态前驱体作为晶种可以促进成核,缩短成核诱导期,有利于获得小晶粒尺寸的TS-1分子筛.此类方法往往需要辅助以大量有机胺等结构导向剂;胶态TS-1前驱体的制备需要特别小心以保证晶种中Ti的四配位状态,通常需要经历低温水解钛酸四丁酯(TBOT)和高温加热除醇等繁琐步骤.而胶态纯硅silicalite-1制备则相对简单,且已广泛用于导向合成同样具有MFI结构的ZSM-5沸石,但目前鲜有以silicalite-1做晶种合成TS-1分子筛的报道.基于此,本文以纯硅胶态silicalite-1为晶种,以氨水做碱源,辅助以少量TPABr做导向剂,合成了小晶粒TS-1分子筛,并以正己烯环氧化和环己酮氨肟化做探针反应考察了所得TS-1分子筛的催化氧化性能. X射线衍射结果表明,当晶种中SiO2占合成体系中SiO2的10 wt%(晶种引入TPAOH, TPAOH/SiO2=0.35),加入TPABr (TPABr/SiO2=0.03)做辅助结构导向剂,即合成体系中总(TPAOH+TPABr)/SiO2摩尔比低至0.07时,所得样品依然具有良好的结晶度.扫描电镜照片观察不到无定形物存在;晶种中SiO2占合成体系中SiO2的10 wt%时,所得TS-1晶粒尺寸约为250 nm ×150 nm ×50 nm;其他条件不变,胶态晶种用量增加到15 wt%时,初级晶粒尺寸基本保持不变,晶粒-晶粒之间交叉生长,形成孪生形貌;继续增加胶态晶种用量至20 wt%时,晶粒尺寸下降至仅100 nm左右;而用20 wt%胶态晶种所含相同量的TPAOH来代替胶态晶种,得到样品呈近10μm的大块状.与之对应的是,胶态silicalite-1晶种导向得到的小晶粒TS-1分子筛具有比直接用TPAOH得到的大块状样品更大的外比表面积和堆积孔体积.分析结果显示所得TS-1分子筛的体相TiO2/SiO2比在41–43.红外光谱和紫外可见光谱结果表明,胶态晶种导向法所得TS-1分子筛中的Ti主要以四配位状态存在,而直接用TPAOH合成的大块状样品则呈现显著骨架外Ti吸收峰,说明胶态晶种有助于Ti物种进入分子筛骨架.在催化正己烯环氧化反应时,用胶态silicalite-1晶种导向得到的小晶粒TS-1分子筛表现出与大块状TS-1相似的催化性能;而以环己酮氨肟化做探针反应时,小晶粒TS-1分子筛因具有外比表面积大和扩散路径短等优点而表现出远远高于大块状TS-1分子筛的催化活性.但与文献报道的相同SiO2/TiO2比的TS-1分子筛比较,本文所得小晶粒TS-1分子筛催化正己烯环氧化的活性略差.提高该小晶粒TS-1分子筛正己烯环氧化活性和建立构-效关系是下一步工作的重点.     

TPAOH改性的微米TS-1表征及其催化性能

采用四丙基氢氧化铵(TPAOH)溶液对微米TS-1进行改性,考察了TPAOH的浓度、处理温度及处理时间等条件对TS-1催化性能的影响.对改性前后的微米TS-1进行了XRD、FT-IR、UV-Vis、SEM、TEM及N2物理吸附等表征,以苯酚羟基化及丁酮氨氧化反应为探针评价了其催化性能.结果表明,改性后的TS-1基本结构没有明显的变化,但在内部出现蚀刻现象.TPAOH改性后的TS-1在苯酚羟基化及丁酮氨氧化反应中的催化性能明显提高.最佳改性条件为,TPAOH溶液浓度0.15 mol/L,改性温度170℃,改性时间48 h.     

无机钛硅原料合成TS-1对环己酮氨氧化的催化性能

考察了无机钛硅原料TS-1合成过程中晶种、促进剂、动静态及样品预处理对催化环已酮氨氧化反应性能的影响．结果表明：合成条件对TS-1样品晶粒尺寸影响较大；样品晶粒尺寸较大而引起的晶内扩散限制是无机钛硅原料TS-1催化性能降低的最主要的原因；样品预处理可以较大幅度地提高环己酮的转化率及肟的收率．在动态加晶种条件下合成的TS-1晶粒较小，经预处理后环己酮的转化率可达97％以上，肟的收率94％以上．     

钛硅分子筛催化1-丁烯环氧化研究

自1983年Taramasso等报导TS-1的合成以来,钛硅分子筛的合成及应用一直是分子筛催化领域的热点。经典TS-1合成方法采用四丙基氢氧化铵（TPAOH）为模板剂,合成成本较高、条件苛刻,限制了其应用。用四丙基溴化铵（TPABr）为模板剂代替TPAOH,能够成功地合成TS-1。不同孔道结构的钛硅分子筛,如Ti-β、Ti-MCM-41、Ti-HMS等弥补了TS-1较小孔径的缺点,进一步扩大了钛硅分子筛的应用。本文以不同合成方法得到的TS-1及中孔Ti—HMS为催化剂,双氧水为氧化剂,1-丁烯环氧化合成1,2-环氧丁烷,研究了不同钛硅分子筛对1-丁烯环氧化反应的催化性能。     

干胶转化法合成条件及磷酸处理对TS-1分子筛性能的影响

以正硅酸乙酯(TEOS)、钛酸丁酯(TBOT)、四丙基氢氧化铵(TPAOH)分别作硅源、钛源及模板剂,用干胶转化法合成TS-1分子筛.考察了TEOS水解时的水硅比、水解温度、除醇条件、晶化时间及磷酸处理对TS-1分子筛性能的影响.采用XRD、SEM、IR、ICP及N2吸附等手段对样品进行表征,同时以环己酮氨肟化反应考察样品的催化活性.结果表明,使用少量的TPAOH(n(TPAOH)/n(SiO2)=0.15)即可得到性能较好的TS-1,而用磷酸对所得TS-1分子筛处理则能进一步改善TS-1分子筛的性能.当n(SiO2):n(TPAOH):n(H2O)=1:0.15:16时在20℃下水解TEOS,钛硅溶液能自行胶凝,将所得凝胶在75℃下除醇至失重率达65%左右,晶化6d得到TS-1分子筛,产品经磷酸改性后,环己酮转化率达到99.5%,环己酮肟选择性达到98.7%,催化活性与高TPAOH用量合成的TS-1接近,而TPAOH的用量大大降低.     

合成条件对TS-1结构及其催化氯丙烯环氧化的影响

采用水热法合成了TS-1分子筛，根据XRD、FT-IR、FT-Raman和UV-Vis的表征结果计算了TS-1的相对结晶度和骨架钛相对含量，并以氯丙烯环氧化反应为探针反应，研究了合成条件对TS-1的结构和催化性能的影响，结果表明，TS-1的结晶度随合成液中Si／Ti比和TPAOH／Si比的增大呈先增大后减小的趋势，TS-1的骨架钛相对含量也随合成液中钛含量的减少呈先增大后减小的趋势，随TPAOH含量的增加TS-1的骨架钛相对含量和非骨架钛含量一直增加，且非骨架钛的类型有所改变．具有较高结晶度和骨架钛含量及较低非骨架钛含量的TS-1的催化性能较好．较好的氯丙烯的转化率和环氧氯丙烷的选择性分别为92．1％和87．5％．     

氢氧混合体系下Ag／TS－1催化剂上丙烯的高效环氧化反应

 在氢氧混合体系中，沉积-沉淀法制备的Ag/TS-1催化剂对丙烯环氧化反应具有高的催化活性和选择性。本文主要考察了载体TS-1的硅钛比和反应温度对催化剂性能的影响。结果表明：当载体TS-1硅钛比为64，反应温度150℃时，2wt%Ag/TS-1催化剂表现出优异的催化性能，丙烯转化率和环氧丙烷选择性可分别达1.37%和93.51%。     

无机钛硅原料合成TS-1催化氯丙烯环氧化反应

采用无机钛硅原料体系合成出了TS-1分子筛,并对TS-1分子筛催化氯丙烯环氧化反应进行了研究.在以甲醇为溶剂的体系中考察了反应时间、反应温度、催化剂用量、氯丙烯与双氧水的摩尔比对反应的影响,得到了无机钛硅原料体系合成的TS-1催化氯丙烯环氧化反应的最优条件:反应时间为60 min,反应温度为45℃,催化剂用量为22.5 g L-1,氯丙烯与双氧水的摩尔比n(AC):n(H2O2)=1.8,并对无机钛硅原料体系合成的TS-1进行了修饰改性,评价了其催化性能.     

表面活性剂Tween对TS-1合成及催化性能影响的研究

以添加吐温的少量四丙基氢氧化铵（TPAOH）为模板剂,水热下合成了钛硅分子筛（TS-1）。采用FTIR、XRD、SEM、BET、UV-Vis等手段对分子筛进行表征。XRD结果表明,所得样品完全晶化,具有典型的MFI拓扑学结构;FTIR结果表明,样品在960 cm－1处出现了强吸收峰,表明钛已进入骨架;UV-Vis谱图表明,所合成样品在330 nm附近没有电子跃迁信号,表明其中没有锐钛矿型TiO2;SEM结果表明所合成样品的晶粒大小均匀。在添加适量吐温所得的胶团溶液中,模板剂分子与吐温之间的协同作用有助于TPAOH与硅、钛源定向反应,避免非骨架TiO2的生成,减少了TPAOH的用量,丙烯环氧化反应结果表明,吐温20、吐温40、吐温60及吐温80等非离子表面活性剂的添加都有助于降低模板剂（TPAOH）的用量和提高TS-1的催化活性,其中吐温40的影响尤为显著,吐温40/TPAOH摩尔比为0.02时,过氧化氢转化率达98.1%,环氧丙烷选择性和收率分别可达96.1％和94.3％。     

无机钛硅原料体系合成TS-1催化丙烯环氧化反应

研究了无机钛硅原料体系合成的ＴＳ－１催化丙烯环氧化的反应,并与经典法、修正法制得样品的催化性能进行了比较。考察了搅拌、Ｎａ２ＣＯ３加入量、反应时间、反应温度、双氧水加量、催化剂量及溶剂等对丙烯环氧化反应的转化率、选择性等的影响,并初步探讨了无机钛硅原料合成的ＴＳ－１的再生性能。结果表明,对于丙烯环氧化反应,无机钛硅原料合成ＴＳ－１样品与经典法和修正法制取样品的催化性能相当;反应条件对丙烯环氧化反应     

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。