活性自由基聚合法制备多壁碳纳米管表面槲皮素分子印迹聚合物及其应用

为了制备能有效分离富集药草中槲皮素的固相萃取柱,以丙烯酰胺(AM)修饰的碳纳米管为载体,三硫代碳酸酯(DBTTC)为可逆加成-断裂链转移剂(RAFT试剂),槲皮素为模板,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,乙腈为致孔剂,制备了槲皮素分子印迹聚合物,采用红外光谱、扫描电镜和热重分析对印迹材料进行表征,通过高效液相色谱(HPLC)研究聚合物的吸附性能和对底物的特异性识别能力。结果表明,通过活性自由基聚合法合成的多壁碳纳米管表面槲皮素分子印迹聚合具有更好的形态结构和吸附性能,且对槲皮素有很好的特异性识别能力。     

不同功能单体合成的分子印迹聚合物识别性能的研究

采用分子印迹技术,用不同的功能单体合成了槲皮素的分子印迹聚合物,测定了它们的吸附性能,并考察了模板分子与功能单体相互作用与印迹聚合物吸附性能的关系。结果表明:在四氢呋喃-氯仿(V/V 8:2)的溶剂体系中以2-乙烯基吡啶(2-VP)为功能单体合成的分子印迹聚合物的吸附性能最强,吸附量为4457.52(μg)/g,通过紫外光谱法测定的结果,在该条件下槲皮素与2-乙烯基吡啶的作用力也是较强的。     

香豆素分子模板聚合物的合成与性能研究

以香豆素为模板分子, α-甲基丙烯酸(MAA)、丙烯酰胺(MA)、2-乙烯基吡啶(2-VP)和4-乙烯基吡啶(4-VP)为功能单体, 二甲基丙烯酸乙二醇酯(EGDMA)为交联剂, 利用分子模板技术分别在甲苯、甲醇、氯仿和乙腈溶剂中合成了一系列香豆素分子模板聚合物(MTP), 研究了聚合体系组成对模板聚合物吸附特性的影响. 结果表明, 在所合成的模板聚合物中, 以MAA为功能单体, 乙腈为致孔溶剂, 以1∶4∶30的摩尔比加入模板分子、MAA及EGDMA时制备的模板聚合物吸附容量高、印迹效果和选择性好. 此模板聚合物有作为白芷样品中香豆素吸附分离材料的应用前景.     

丹酚酸A分子印迹聚合物制备及识别性能研究

以丹酚酸A为模板分子,丙烯酰胺(AM)、α-甲基丙烯酸(MAA)、2-乙烯基吡啶(2-VP)和4-乙烯基吡啶(4-VP)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,丙酮、乙酸乙酯、乙腈和甲醇为致孔剂,采用本体聚合法制备了一系列丹酚酸A分子印迹聚合物.通过静态平衡吸附实验和选择性实验考察了印迹聚合物的吸附性能...     

林可霉素分子印迹聚合物的制备及吸附性能研究

以林可霉素(LIN)为模板,利用分子模拟方法模拟丙烯酰胺(AM)、甲基丙烯酸(MAA)、2-乙烯基吡啶(2-VP)和4-乙烯基吡啶(4-VP)4种常见的功能单体与模板分子的结合能,结果表明4-VP结合能最强为-98.25 kJ/mol。用悬浮聚合法制备林可霉素分子印迹聚合物(MIP)并对其性能进行评价。使用气相色谱检测各功能单体制备的印迹聚合物的吸附量,结果4-VP制备的印迹聚合物吸附量最大为102.8μmol/g,分子模拟结果与吸附试验结果一致,表明分子模拟可以为功能单体选择提供依据。采用静态吸附试验和动态吸附试验对印迹聚合物吸附性能表征,并进行了Scatchard模型分析。结果印迹因子为2.54,并且在150 min内较快地达到吸附平衡,表明林可霉素分子印迹聚合物具有较高的选择吸附性,可用于林可霉素的富集。     

可逆加成-断裂链转移自由基聚合研究进展

综述了活性/可控自由基聚合中的可逆加成-断裂链转移(RAFT)自由基聚合研究进展;总结了RAFT试剂、RAFT聚合反应条件、RAFT聚合物及其结构形貌的最新研究进展;指出RAFT自由基聚合反应已被作为重要方法之一用于合成具有特定分子结构的聚合物.     

表面分子印迹高分子膜修饰硅胶用于血清中茶碱的固相萃取

采用表面引发可逆加成-断裂链转移自由基聚合反应,在硅胶表面修饰了分子印迹高分子膜(MIP-silica)。以元素分析和氮吸附分析对修饰的分子印迹高分子膜进行了表征。与传统采用本体聚合合成的分子印迹高分子相比,MIP-silica具有更好的传质能力。本文合成的茶碱印迹MIP-silica可以作为选择性固相萃取材料从血清中富集、检测微量的茶碱,该法合成的MIP-silica还可用于高效液相色谱和毛细管电色谱等领域。     

染料木素分子印迹聚合物的制备及其识别性能

以染料木素为模板分子、4-乙烯基吡啶(4-VP)为功能单体、乙二醇二甲基双丙烯酸酯(EGDMA)为交联剂、四氢呋喃(THF)为溶剂,采用本体聚合法制备了染料木素的分子印迹聚合物;采用静态平衡结合实验研究了该分子印迹聚合物对染料木素的结合能力和选择性能.结果表明,与化学组成相同的相应非印迹聚合物相比,染料木素分子印迹聚合物对染料木素的吸附性能和选择性更好.利用所合成的分子印迹聚合物作为固相萃取材料填充固相萃取小柱,可以选择性地从豆奶粉中分离、富集染料木素;此外,该分子印迹聚合物还有望用于其他豆制品的分析检验.     

活性/可控自由基聚合制备恩诺沙星印迹微球及识别性能研究

研究了一种以活性／可控自由基聚合（可逆加成一断裂链转移自由基聚合,reversible addition-fragmentation chain transfer radical polymerization,RAFT polymerization）制备分子印迹微球的方法。结合沉淀聚合法,以二硫代苯甲酸异丙苯酯（cumyl dithiobenzoate,CDB）为可逆加成一断裂链转移剂,恩诺沙星为印迹化合物,甲基丙烯酸（MAA）和乙二醇二甲基丙烯酸酯（EDMA）分别为功能单体和交联剂,偶氮二异丁腈（AIBN）为引发剂,乙腈为分散剂,考察了温度、单体浓度等反应条件对微球制备的影响。通过改变AIBN和CDB的比例,可以达到控制分子印迹微球粒径和分散性的目的。扫描电镜结果显示,以RAFT聚合法得到的分子印迹微球粒径可达2．0～2．2μm,并有良好的分散性。平衡吸附实验结果说明印迹聚合物微球对印迹化合物的结合能力优于非印迹聚合物。分子印迹微球对于恩诺沙星及其结构类似物洛美沙星的饱和吸附量分别为37．3和19．5μmol·g^-1,证明分子印迹微球有很好的识别能力。     

含氟聚合物的合成进展

含氟聚合物由于其优异的化学和物理性能以及广泛的应用前景而受到关注。根据聚合反应单体结构不同,可以通过不同方法合成各种结构的含氟聚合物。这些聚合方法主要是可控／“活性”聚合,例如：原子转移自由基聚合（ATRP）、原子转移自由基一乙烯基自缩合聚合（ATR—SCVP）、可逆加成一断裂链转移聚合（RAFT）、氮氧稳定自由基聚合...     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

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.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

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。