壳聚糖复合膜及异丙醇／水混合液的渗透汽化分离

用磺化聚乙烯离子膜渗透汽化分离恒沸组成的i-PrOH/H_2O(87.2/12.8W/W),分离系数α高,渗透通量J低(小于300g/m~2·h,40℃),当醇含量高于90％时,膜性能变差;用CA膜、赛璐玢膜[2]、Nation-Na~+膜,J较高,α低(<30)。甲壳素脱乙酰基产物壳聚糖(Chitosan,简称CS),易交联改性,成膜性好。CS膜分离i-PrOH/H_2O,α很高,而J低。经戊二醛交联的CS膜尺寸稳定,增加了醇/水的J值,α虽有所下降,对i-PrOH/H_2O体系仍具有很高的值。为了进一步提高J值,我们研制了以聚丙烯腈(PAN)微孔膜作支撑的CS复合膜,     

用聚电解质渗透汽化膜进行乙醇脱水

渗透汽化 (PV)膜过程由于可用于有机 /有机及有机 /水的恒沸或近沸混合物的分离而成为近年来膜技术研究开发的热点[1,2 ] .德国 GFT公司所制的富马酸交联 PVA脱水膜[3] 对温度为 80℃的 80 %Et OH料液 ,其分离因子为 350 ,渗透通量为 2 0 0 g/ (m2 ·h) .优秀的分离膜要求渗透通量大 ,同时具有较高的分离因子和良好的稳定性 .因此 ,提高膜的分离性能是渗透汽化技术开发应用的关键 .周继青等 [4 ]研究了 PVA/ PVP互穿网络膜的渗透汽化性能 ,发现膜的渗透通量虽有明显提高 ,但膜的选择性下降 .聚电解质具有优良的亲水性 ,可制得高水通…     

聚乙烯醇(PVA)/壳聚糖(CS)合金膜的醇-水渗透汽化分离性能研究

在表征了PVA/CS共混体系相容性的基础上,本文报导MeOH-H_2O,EtOH-H_2O和i-PrOH-H_2O体系在PVA,CS及其合金膜中的渗透汽化行为。讨论了温度、料液浓度、合金膜的组成对分离性质的影响。从膜的分子和聚集态结构出发对相关的渗透行为进行了解释。对于PVA、CS及其合金膜来说,膜内自由体积大小看来是影响分离性能的主要因素,小分子在膜中的渗透性质主要是由扩散控制的。     

改性壳聚精膜用于醇水混合液分离的研究──Ⅲ．超细粉末填充壳聚精膜

首次制备了用Ｓｉ３Ｎ４，ＳｉＯ２，ＴｉＨ４超细粉末填充的改性壳聚精膜，并将其用于乙醇／水混合液的分离中。实验表明壳聚糖膜经超细粉末填充后强度增大，溶胀度减小。用于乙醇／水混合液渗透蒸发分离时，分离因子和渗透通量都有提高，并在填充量为１６．７％附近出现极大值。随着料液中乙醇含量的增大，渗透通量减小，分离因子增大；随着料液温度的升高渗透通量显著增大，分离因子则稍有下降。并简单讨论了超细粉末在乙醇／水混合液分离中的作用。     

莫来石管上丝光沸石膜的合成与渗透汽化性能

采用不添加有机模板剂、配比为n_(Na_2O):n_(Al_2O_3):n_(SiO_3):n_(H_2O)=0.25:0.015～0.1:1:15～60溶胶,在涂有晶种的多孔莫来石管上水热合成出了丝光沸石膜。制备的膜经XRD和SEM表征。考察了合成时间、硅铝比、水硅比和硅源等因素对膜生长及其性能的影响。合成时间的延长有利于丝光沸石c轴方向的优先生长,然而优先取向生长膜层并未提高膜在水/乙醇分离体系中的渗透通量和选择性。优化条件下合成的膜具有较高的渗透汽化性能,在348 K、水/乙醇(10/90,W/W)混合溶液中的渗透通量和分离因子分别为0.70 kg·m~(-2)·h~(-1)。和860。基于XRD和SEM表征结果,高的渗透汽化性能可归结于在莫来石支撑层与较为疏松的表面晶体层之间形成的致密中间层。     

交联聚乙烯醇膜材料中水的状态及其分离特性

以DCS分析了不同交联度的马来酸交联PVA模材料中结晶结合水的凝固点,及其交联度大小对高分子链与水分子间氢键强弱的影响,研究了不同交联度的PVA／PAN复合膜对乙醇一水的渗透汽化分离性能影响。结果表明,结晶结合水的凝固点越低,水分子与高分子链间的氢键作用越强;PVA／PAN复合膜的渗透通量随PVA交联度的增大而降低,分离系数则随交联度的增大而提高。     

含氟体系下高性能丝光沸石分子筛膜的制备及其性能

采用热涂-浸渍法在大孔α-Al2O3载体上形成薄且致密的晶种层,然后在不添加有机模板剂的含氟条件下二次水热生长法制备了高性能丝光沸石分子筛膜,考察了NaF含量、硅/铝比对丝光沸石分子筛膜形貌和性能的影响.将摩尔组成为6Na2O:1.2Al2O3:30SiO2:780H2O:1.5NaF条件下合成的丝光沸石分子筛膜用于渗透汽化分离91.5%乙醇/水体系,在渗透汽化温度70°C、真空度为400Pa条件下,分离因子和通量分别达到了6872和0.51kg/(m2·h);另外,在分离异丙醇/水、乙酸/水体系时,渗透侧水浓度达到了100%(在色谱检测极限范围内),该分离系数是目前报道的丝光沸石分子筛膜分离的最佳值,并在乙酸浓度为1mol/L的乙醇水溶液中表现出良好的耐酸性.该膜有望作为膜反应器在乙酸乙酯等酯类的生产中大大提高转化率.     

低温氧等离子体改性海藻酸钠膜分离乙醇—水溶液

研究了氧等离子体对海藻酸钠膜的表面改性，并将该膜用于渗透汽化分离乙醇－水溶液。通过红外光谱、表面电阻、接触角等手段测试，表明在海藻酸钠膜表面增加了羟基、羧基及羰基，因而更加亲水。当分别用未处理的原始膜，氧等离子体处理膜处理表面对着原料液，以及处理表面对着减压侧用于渗透汽化法分离乙醇－水混和物时，性能明显不同。其结果是：上表面处理后，渗透通量明显增加，分离系数也较未处理略高；下表面处理后，渗透速度下     

壳聚糖膜结构与乙醇／水混合液的渗透汽化性能

用渗透汽化膜分离混合液体,纤维素、赛璐玢等作醇/水分离膜有较高的渗透通量,但分离系数低.甲壳素是广泛存在于自然界的一类天然高分子.前文报道了用甲壳素脱乙酰基的产物壳聚糖(CS)作醇/水渗透汽化(PV)分离膜,在一定的原料液浓度下具有较好的选择渗透性.本文讨论CS膜结构对乙醇/水混合液PV性能的影响,并探讨了提高选择性的途径.     

聚合物支撑的金属有机骨架膜的制备及其气体分离性能

由于MOF(金属有机骨架)膜与基底之间的作用力较薄弱,所以制备具有高的H_2渗透性和H_2/CO_2选择性的致密连续的大面积金属有机骨架膜仍具有巨大挑战。本文选取多孔Al_2O_3作为基底,在表面涂覆一层PIM-1(一种固有微孔聚合物),并对其进行羧基化处理,使得表面具有大量的羧基基团,随后利用羧基与金属之间的相互作用,原位生长得到了两种致密连续的聚合物支撑的MOF膜(PIM-1-COOH/ZIF-8和PIM-1-COOH/HKUST-1)。通过XRD的表征可以看出MOF膜是纯相的并且具有较高的结晶性;SEM的测试结果表明MOF膜是致密连续的并且MOF膜与基底之间紧密结合。气体分离测试结果表明,这两种MOF膜对H_2具有较高的渗透性以及H_2/CO_2选择性。在常温常压下,对于PIM-1-COOH/ZIF-8和PIM-1-COOH/HKUST-1膜,H_2/CO_2双组分气体的分离系数分别为7.32、9.69,并且它们H_2的渗透通量分别高于3.16×10~(-6)、1.14×10~(-6) mol·m~(-2)·s~(-1)·Pa~(-1)。在单组份测试中,这两种MOF膜的H_2/CO_2的理想分离系数分别为7.70、12.04;H_2的渗透通量分别高达3.73×10~(-6)、3.86×10~(-6) mol·m~(-2)·s~(-1)·Pa~(-1),这就表明这两种MOF膜有望在H_2的纯化和分离方面广泛应用。     

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。