交联壳聚糖树脂与Zn2+的配位作用

研究了甲醛、环氧氯丙烷交联壳聚糖树脂(Chitosan crosslinked by aldehyde and epichlorohydrin,AECTS)吸附Zn2 后对树脂结构及性能所产生的影响.用FTIR、XRD、TG、DSC和SEM对吸附产物进行了结构表征,并分析了AECTS与Zn2 之间的作用机理.结果表明,Zn2 与AECTS中的氨基发生配位而被吸附;AECTS吸附Zn2 后,结晶度下降、总体上热稳定性变差;Zn2 对AECTS的主链分解具有明显的催化功能;Zn2 的配位使得AECTS的表面形态发生了改变.     

交联壳聚糖树脂与Zn2+的配位作用

研究了甲醛、环氧氯丙烷交联壳聚糖树脂(Chitosan crosslinked by aldehyde and epichlorohydrin,AECTS)吸附Zn2 后对树脂结构及性能所产生的影响.用FTIR、XRD、TG、DsC和SEM对吸附产物进行了结构表征,并深入分析了AECTS与Zn2 之间的作用机理.结果表明,Zn2 与AECTS中的氨基发生配位而被吸附;AECTS吸附Zn2 后,结晶度下降、总体上热稳定性变差:Zn2 对AECTS的主链分解具有明显的催化功能;Zn2 的配位使得AECTS的表面形态发生了改变.     

交联壳聚糖对Zn2+的吸附性能

研究了甲醛、环氧氯丙烷交联壳聚糖树脂(AECTS)对Zn 2 的吸附行为,探讨温度、溶液的pH、反应时间、再生次数等因素对吸附性能的影响,并用红外光谱(FTIR)和光电子能谱(XPS)对吸附产物表面的元素结构及其结合能的变化进行表征. 结果表明,AECTS对Zn 2 的吸附导致AECTS结构和性能发生显著变化. FTIR和XPS分析表明,Zn 2 以配位键的形式吸附于AECTS,使AECTS中氨基的伸缩振动、变形振动发生了明显变化,N原子发生化学位移,而AECTS分子链上的羟基没有直接参与配位反应;AECTS对Zn 2 有较强的吸附能力和较快的吸附速率,在30 ℃、Zn 2 初始质量浓度为1 g/L的溶液中,吸附量可达163 mg/g树脂,是壳聚糖饱和吸附量的1.7倍左右;吸附量受pH的影响较大,在pH＝5时吸附量最高;AECTS对Zn 2 的吸附行为符合Freundlich等温吸附方程,温度升高吸附量增大,该过程为一吸热过程;AECTS经再生重复使用5次,吸附量基本不变.     

交联壳聚糖-Co配聚物结构与性能初步研究

制备了微球状交联壳聚糖并合成了交联壳聚糖(AECTS)-Co配聚物。用FTIR、WXRD、TGA和DSC等对配聚物进行了结构表征。结果表明：Co^2 与AECTS中的氨基、羟基发生配位而被吸附;树脂与Co^2 配位后,结晶度下降、热稳定性降低。     

交联壳聚糖树脂吸附Co2+的机理研究

研究了甲醛、环氧氯丙烷交联壳聚糖 (AECTS) 对Co2 的吸附热力学行为,用FTIR、WXRD对吸附产物进行了结构表征,并研究了溶液中介质种类的不同对Co2 吸附量的影响.结果表明:AECTS主要以配位吸附和物理吸附形式吸附Co2 ;树脂与Co2 配位后,结晶度下降;AECTS对Co2 的吸附行为同时符合Freundlich模型和Langmuir模型;吸附为自发的、放热的熵减小过程;不同介质对树脂吸附Co2 的影响大小顺序为HCl>CdCl2>MgCl2>NaCl,前两者使吸附量减小,后两者使吸附量增加,作用机理相差较大.     

交联壳聚糖树脂对Ni(II)的吸附行为研究

研究了甲醛、环氧氯丙烷交联壳聚糖树脂(AECTS)对Ni(II)的吸附行为和吸附Ni(II)对树脂结构及性能的影响.用FTIR,WAXD,TGA和DSC对吸附产物进行了结构表征,并深入分析了AECTS与Ni(II)之间的作用机理.结果表明:AECTS主要以配位形式吸附Ni(II);AECTS吸附Ni(II)后,结晶度下降、总体上热稳定性变差;Ni(II)对AECTS的主链分解具有明显的催化功能,而空气气氛中对AECTS在500℃附近的分解表现出火焰缓蚀作用.AECTS对Ni(II)的吸附行为符合Langmuir模型,属于单分子层吸附,所有吸附位对Ni(II)的作用近似相同;与壳聚糖(CTS)比较,造成AECTS对Ni(II)吸附量增大的主要原因是AECTS结晶度下降和孔隙率增加,二者导致在交联处理前Ni(II)难于接近的吸附位点“活性”相对增大,使其更容易与Ni(II)相结合;不同介质对AECTS吸附Ni(II)的影响大小顺序为HCl>CdCl2>MgCl2>NaCl,前两者使吸附量减小,MgCl2使吸附量稍有增加,NaCl对吸附量基本没有影响.     

交联壳聚糖树脂对Ni(II)的吸附行为研究

研究了甲醛、环氧氯丙烷交联壳聚糖树脂(AECTS)对Ni(II)的吸附行为和吸附Ni(II)对树脂结构及性能的影响. 用FTIR, WAXD, TGA和DSC对吸附产物进行了结构表征, 并深入分析了AECTS与Ni(II)之间的作用机理. 结果表明: AECTS主要以配位形式吸附Ni(II); AECTS吸附Ni(II)后, 结晶度下降、总体上热稳定性变差; Ni(II)对AECTS的主链分解具有明显的催化功能, 而空气气氛中对AECTS在500 ℃附近的分解表现出火焰缓蚀作用. AECTS对Ni(II)的吸附行为符合Langmuir模型, 属于单分子层吸附, 所有吸附位对Ni(II)的作用近似相同; 与壳聚糖(CTS)比较, 造成AECTS对Ni(II)吸附量增大的主要原因是AECTS结晶度下降和孔隙率增加, 二者导致在交联处理前Ni(II)难于接近的吸附位点“活性”相对增大, 使其更容易与Ni(II)相结合; 不同介质对AECTS吸附Ni(II)的影响大小顺序为HCl＞CdCl₂＞MgCl₂＞NaCl, 前两者使吸附量减小, MgCl₂使吸附量稍有增加, NaCl对吸附量基本没有影响.     

交联壳聚糖树脂吸附Cu2+的机理研究

研究了甲醛、环氧氯丙烷交联壳聚糖(AECTS)对Cu2+的吸附热力学行为,用FTIR对吸附产物进行了结构表征,并研究了溶液中介质种类的不同对Cu2+吸附量的影响.结果表明AECTS主要以配位形式吸附Cu2+;AECTS对Cu2+的吸附符合Langmuir等温方程,属于单分子层吸附;吸附为自发的、吸热的熵增加过程;同时不同介质对树脂吸附Cu2+的影响大小顺序为HCl＞CdCl2＞MgCl2＞NaCl,并对其作用机理进行了探讨.     

弱酸性氨基二硫代甲酸酯功能化聚氯乙烯树脂对Hg2+的吸附与脱附性能

以聚氯乙烯为原料依次与四乙烯五胺、CS2和ClCH2COONa反应合成了一种含氮、氧、硫的弱酸性氨基二硫代甲酸酯功能化的聚氯乙烯螯合树脂,树脂的结构经红外分析和元素分析表征。探讨了在不同pH值、Hg2+初始浓度、吸附温度和时间等条件下合成树脂对Hg2+的吸附性能。结果表明,螯合树脂对Hg2+有较快的吸附速率,pH=2.0左右时树脂对Hg2+的吸附效果最好,随着温度的升高吸附量逐渐增大,35 ℃时Hg2+起始浓度为0.01766 mol/L时,树脂对Hg2+的吸附量可达3.330 mmol/g。树脂对Hg2+的吸附符合Langmuir和Freundlich等温式。用0.2 mol/L硝酸-10%硫脲对吸附后的树脂进行洗脱,脱附率达99.2%。     

巯基树脂对金属离子的吸附性能(Ⅱ)

研究了自合成的巯基树脂对重金属离子Ag 、Hg2 、Cr3 的吸附容量、吸附动力学、等温吸附过程等静态吸附性能,影响吸附的因素和吸附机理.结果表明,该树脂对上述3种离子吸附能力强,吸附量分别达6.56mmol/g、3.25mmol/g、2.10mmol/g.树脂对各重金属离子等温吸附在实验浓度范围内符合Langmuir或Freundlich方程.吸附机理研究表明,巯基与金属离子发生了离子交换和配位反应,化学吸附起支配作用;另外树脂对Ag 、Hg2 吸附过程中存在一定的氧化还原现象.     

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。     

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.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

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.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

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^-。     

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.