Fe3O4/壳聚糖复合纳米粒子吸附剂的制备及其对Pb2+吸附性能

用乙二醇为溶剂,三氯化铁和尿素为起始反应试剂,柠檬酸为粒子表面修饰剂,通过一步溶剂热法制备Fe3 O4纳米粒子,然后以一定浓度配比的Na2 SO4与NaOH混合液为沉淀剂,通过沉淀聚合法制备Fe3 O4/壳聚糖复合纳米粒子吸附剂。利用X射线衍射仪(XRD)、红外光谱(IR)、透射电子显微镜(TEM)和物理特性测试仪(PPMS)表征样品的结构、形貌和磁性能,并使用原子吸收分光光度计(AAS)评价吸附剂对Pb2+的吸附去除性能。结果表明,Fe3O4/壳聚糖复合纳米粒子吸附剂是由磁性Fe3O4纳米球形粒子和鱼卵状壳聚糖纳米粒子聚集体复合而成,该吸附剂对Pb2+有很好的吸附去除性能,它对Pb2+的等温吸附线符合Langmuir模型,在温度298k和pH值5时,吸附剂对Pb2+的饱和吸附量为105.5mg/g。     

基于Fe_3O_4-Au磁性纳米粒子及碳纳米管修饰电极的对氧磷生物传感器研究

采用化学共沉淀技术制备磁性Fe3O4-Au纳米粒子复合物(Fe3O4-AuNPs),并以此磁性纳米复合物和碳纳米管(CNTs)构建用于快速检测对氧磷的乙酰胆碱酯酶(AChE)生物传感器。通过磁力作用将Fe3O4-AuNPs纳米粒子固定在自制的磁铁/玻碳电极(MGCE)上,并以此作为AChE的载体。分别通过X射线衍射、振动样品磁强和透射电镜表征了磁性纳米粒子复合物Fe3O4-AuNPs的成分、磁性及其形貌特征。利用电化学交流阻抗(EIS)、循环伏安法和微分脉冲伏安法(DPV)表征了自制的MGCE修饰电极以及生物传感器(AChE/Fe3O4-AuNPs/CNTs/MGCE)的电化学特征,建立了用该生物传感器微分脉冲伏安法检测对氧磷的方法。在最佳实验条件下,酶抑制率与对氧磷浓度的对数在3.6×10-6~2.9×10-2mol/L范围内呈线性关系,检出限为1.6×10-7mol/L。用提出的方法对实际水样中的对氧磷进行加标回收实验,回收率为98.0%~107%。     

新型磁性纳米金修饰过氧化氢生物传感器的研制

利用共沉淀法合成纳米Fe3O4颗粒,将半胱氨酸吸附到纳米Fe3O4微粒表面,借助半胱氨酸的巯基(-SH)对纳米金的强烈吸附,使纳米金自组装到磁性颗粒上,再通过静电吸附作用自组装辣根过氧化酶(HRP),合成了Fe3O4/Cys/Au/HRP纳米复合粒子,最后通过磁力将其修饰到固体石蜡碳糊电极表面,制得新型过氧化氢生物传感器.以对苯二酚作为电子媒介,用计时电流法对H2O2进行测定,线性范围为2.4 X10-3～6.0×10-6mol/L,检出限(S/N=3)为2.5 X 10-6mol/L,响应时间小于10 s.磁性纳米微粒Fe3O4/Cys/Au能够高效地保持HRP的生物活性.该新型传感器已用于实际样品测定.     

新型金纳米材料在过氧化氢传感器中的应用

合成了新型的金纳米盒子材料,在金电极上通过金硫键自组装的方法修饰金纳米,再通过自组装和浸渍的方法修饰细胞色素c(Cyt c),构建了基于Cyt c的直接电子传递的H2O2电化学传感器,所得传感器的灵敏度为4.4A/(mol/L),线性范围为4.7×10-6~8.0×10-3 mol/L,检测限为1.5×10-6 mol/L。并将以金纳米盒子为基底的传感器与传统的电沉积金纳米,以及金纳米溶胶传感器做了对比,实验结果表明新型的金纳米盒子所修饰的传感器具有更好的灵敏度、更宽的线性范围及更低的检测限。     

电沉积纳米ZnO修饰玻碳电极交流阻抗法测定硫离子

以Zn(NO3)2和KCl为支持解液,在裸玻碳电极(GCE)上电化学沉积一层纳米Zn O薄膜,制备出一种基于纳米Zn O修饰电极(Zn O/GCE)用于检测S2-的电化学传感器。电化学循环伏安法(CV)表明该修饰电极具有大的比表面积及良好导电性能。将Zn O/GCE置于微酸性的Na2S(p H 6.5)溶液中进行富集反应12 min后,可得到恒定的电化学交流阻抗值(Ret)。在最优实验条件下,该制备电极可成功应用于检测不同浓度的Na2S溶液,其ΔRet值与Na2S浓度范围(1.0×10-7~1.0×10-3mol/L)的对数呈良好的线性关系,检出限为6.37×10-8mol/L。制备电极(Zn O/GCE)可应用于实际水样中硫化物的检测。     

AOPAN/PA-66复合纳米纤维膜的制备及对金属离子的吸附性能

采用双喷头电纺丝技术,将尼龙(PA-66)纤维增强的聚丙烯腈(PAN)纳米纤维膜(PAN/PA-66)与盐酸羟胺进行偕胺肟化反应,制备了一种偕胺肟化聚丙烯腈/尼龙复合纳米纤维膜(AOPAN/PA-66).通过红外光谱及扫描电子显微镜等方法研究了偕胺肟化前后纳米纤维膜的组成、形貌和力学性能;并考察了AOPAN/PA-66复合纳米纤维膜对铜离子和铅离子的吸附性能.结果表明,AOPAN/PA-66复合纳米纤维膜的抗拉伸强度及断裂伸长率分别为4.73 MPa和30.76%,对Cu(Ⅱ)及Pb(Ⅱ)的吸附量分别为67.5和75.4 mg/g.     

聚吡咯/尼龙6纳米纤维膜对Pb2+固相萃取的吸附效能研究

以电纺尼龙6纳米纤维膜为基底,原位氧化聚合制得聚吡咯/尼龙6纳米纤维膜(PPy/Nylon 6-NFsM).通过静态和动态吸附实验考察PPy/Nylon 6-NFsM对Pb2+的吸附行为,探究其作为固相萃取介质富集水中痕量Pb2+的可行性.结果表明:298 K,pH=10时,PPy/Nylon 6-NFsM对Pb2+的静态饱和吸附量达542 mg/g;吸附动力学和吸附等温线分别符合准二级动力学模型和Freundlich模型;优化了PPy/Nylon 6-NF-sM的固相萃取条件,采用火焰原子吸收光谱法检测实际水样中的Pb2+,检出限为1.2 μg/L(信噪比为3计),10 μg/L加标水平加标回收率为95.3％ ～ 100.4％,相对标准偏差(RSD)为1.6％(n=3),可实现实际水样中痕量Pb2+的准确、灵敏的检测.     

基于自组装L-半胱氨酸与纳米金的H2O2生物传感器

通过在金电极表面自组装L-半胱氨酸,再分别吸附纳米金与辣根过氧化物酶(HRP)的方法,成功的制备了H2O2生物传感器.采用循环伏安法考察了传感器的电化学特性,电极对H2O2在浓度为2.1×10-6～3.6×10-3 mol/L的范围内呈线性,检出限为8.9×10-7 mol/L (S/N＝3).该传感器具有稳定性好,线性范围宽,检出限低等优点,同时具有一定的抗干扰能力.     

基于胆碱修饰层为基底的纳米金固定过氧化物酶修饰电极的研究

玻碳电极上共价修饰上单分子层胆碱(Ch)可以显著提高电极的活性。本研究利用该电极上胆碱层带有的正电荷,牢固吸附带负电荷的纳米金溶胶,继而利用纳米金颗粒良好固载辣根过氧化物酶(HRP),制备出了基于HRP酶直接电化学的H2O2传感器。以阻抗谱、循环伏安等方法表征了修饰电极的性质。结果显示,该电化学传感器具有良好的催化活性,电活性HRP的表面浓度(Γ*)为1.2×10-9mol/cm2,米氏常数KMapp=1.55±0.11 mmol/L。该修饰电极在H2O2浓度1.2×10-6~3.2×10-3mol/L范围内有线性响应,检出限(S/N=3)为4.0×10-7mol/L。本修饰电极制备简单,选择性高,稳定性好,可以作为进一步构筑生物传感器的基础。     

纳米B2O3/TiO2复合材料的制备及其对痕量银的分离富集性能研究与应用

制备了新型纳米B2O3/TiO2吸附材料,并采用扫描电镜(SEM)及红外光谱(IR)对其进行表征,优化了纳米B2O3/TiO2复合材料对试液中痕量银的吸附和解吸条件,建立了纳米B2O3/TiO2分离富集-原子吸收光谱测定痕量银的新方法。当pH 4.3时,在22℃下振荡20 min,Ag+能被该材料快速吸附,其静态饱和吸附容量为11.72 mg/g,吸附在纳米B2O3/TiO2上的Ag+可用0.1 mol/L HNO3-0.05 mol/L硫脲(1∶4)完全洗脱。该方法的检出限为2.01μg/L,线性范围为0.01～4.00 mg/L,相对标准偏差(RSD)为1.8%,加标回收率为95%～105%。方法应用于实际矿渣样品中痕量银的测定,结果满意。     

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.     

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。