交联壳聚糖对重金属离子吸附性能的研究进展

壳聚糖分子中含有大量的氨基和羟基,可以进行多种化学改性.本文综述了四类交联剂(醛类、环氧氯丙烷、聚乙二醇类以及冠醚)交联壳聚糖对重金属离子的吸附研究进展.从吸附剂在酸性条件下的稳定性、对某种或者某些离子的选择吸附性能、吸附容量以及可再生能力等方面讨论了各种吸附剂的性能.此外,加强吸附机理研究是今后研究的方向之一.     

硅胶的表面硫醇化改性及对水溶液中罗丹明B的固载

运用γ-巯丙基三乙氧基硅烷对硅胶表面硫醇化修饰改性,红外及拉曼光谱分析表明硅胶的表面硫醇化借助硅胶表面羟基与γ-巯丙基二乙氧基硅烷间的化学键联实现。实验条件下改性硅胶对水体罗丹明B的吸附性能明显提升,改性硅胶表面罗丹明B的吸附动力学符合准二级动力学模型,吸附等温线服从Langmuir等温线规律,由等温吸附计算得到的热力学函数变化表明吸附系自发、放热过程。吸附动力学、热力学及光谱表征均表明改性硅胶上罗丹明B的吸附主要为其在改性硅胶表面借助电价和共价键联的化学吸附。     

活性炭的改性研究及对四环素的吸附

研究了改性对活性炭的物理化学性质及其对四环素吸附性能的影响。结果发现,硝酸氧化改性可增加活性炭表面的酸性基团,提高比表面亲水性,降低pHPZC值,同时也改变了活性炭的表面微观形貌。低温、低浓度硝酸氧化改性,增加了活性炭的比表面积,对四环素的吸附以物理吸附为主。高温氧化改性使得比表面积降低,酸性基团增加,且吸附容量与活性炭比表面积、表面总酸度呈一定的线性关系。     

表面活性剂改性有机沸石对废水中亚甲基蓝的吸附行为

用表面活性剂十六烷基三甲基溴化铵(CTMAB)和十二烷基硫酸钠(SDS)复合改性沸石,制备了阴阳离子表面活性剂改性沸石,利用X射线衍射和红外吸收光谱表征了改性前后沸石的结构,并研究了改性沸石对亚甲基蓝的吸附行为.结果表明,改性后沸石的吸附性能明显增强;在溶液pH 8、常温,吸附时间100 min、改性沸石用量20 g/...     

镧、铈改性沸石对污水除磷性能和机制的比较研究

稀土改性沸石除磷作为一种高效的除磷吸附剂已经被广泛地关注。但是,La和Ce改性沸石在吸附性能和除磷机制上的差异却未见报道。通过制备La和Ce改性商业购天然斜发沸石颗粒用于废水除磷,比较了二者的吸附能力、吸附动力学、物理性质、晶型、表面特征。研究表明:经过La和Ce改性的沸石吸附量提高了将近10倍,Ce改性沸石的吸附量略高于La改性沸石的吸附量。动力学拟合结果表明:La改性沸石对磷的吸附更符合伪二级动力学方程,而Ce改性沸石对磷的吸附更符合伪一级动力学。电镜和能谱分析发现Ce的负载量高于La的负载量。La和Ce都堆积在沸石表面,并未浸渍到沸石的孔径中。由于Ce在沸石表面的大量堆积增加了其比表面积,提高了其对磷的吸附能力。La和Ce改性沸石都形成了相同的晶体,二者具有相同的除磷机制。     

硅胶的表面硫醇化改性及对水溶液中罗丹明B的固载（英文）

运用γ-巯丙基三乙氧基硅烷对硅胶表面硫醇化修饰改性,红外及拉曼光谱分析表明硅胶的表面硫醇化借助硅胶表面羟基与γ-巯丙基二乙氧基硅烷间的化学键联实现。实验条件下改性硅胶对水体罗丹明B的吸附性能明显提升,改性硅胶表面罗丹明B的吸附动力学符合准二级动力学模型,吸附等温线服从Langmuir等温线规律,由等温吸附计算得到的热力学函数变化表明吸附系自发、放热过程。吸附动力学、热力学及光谱表征均表明改性硅胶上罗丹明B的吸附主要为其在改性硅胶表面借助电价和共价键联的化学吸附。     

硅胶的表面硫醇化改性及对水溶液中罗丹明B的固载

运用γ-巯丙基三乙氧基硅烷对硅胶表面硫醇化修饰改性, 红外及拉曼光谱分析表明硅胶的表面硫醇化借助硅胶表面羟基与γ-巯丙基二乙氧基硅烷间的化学键联实现。实验条件下改性硅胶对水体罗丹明B的吸附性能明显提升, 改性硅胶表面罗丹明B的吸附动力学符合准二级动力学模型, 吸附等温线服从Langmuir等温线规律, 由等温吸附计算得到的热力学函数变化表明吸附系自发、放热过程。吸附动力学、热力学及光谱表征均表明改性硅胶上罗丹明B的吸附主要为其在改性硅胶表面借助电价和共价键联的化学吸附。     

PNIPAAm改性表面对蛋白质吸附的调控及其应用

根据不同领域的需要,控制蛋白质在材料表面的吸附是一个具有重要应用价值的课题。聚（N-异丙基丙烯酰胺）（PNIPAAm）改性表面能够响应外界温度变化从而改变其表面性质,这一特点为调控蛋白质的吸附提供了可能。近年来,研究者们应用多种表征方法考察了不同温度下蛋白质在PNIPAAm改性表面的吸附,并试图从分子水平上深入理解其吸附机制及影响因素。本文综述了近年来应用PNIPAAm改性表面对蛋白质吸附的研究及其最新进展。发现当PNIPAAm层厚度处于一定范围内时,PNIPAAm改性表面表现出对蛋白质吸附的温度敏感性,并可以利用这一性质将其应用于蛋白质纯化及分离和生物传感器等领域。而当PNIPAAm层厚度超过一个临界值时,PNIPAAm改性表面表现出良好的阻抗血浆蛋白质的性质,使其有望在血液相容性表面领域得到应用。最后,就PNIPAAm改性表面调控蛋白质吸附的未来发展方向简要地进行了展望。     

MCM-41分子筛的改性、表面结构与吸附性质的研究

用三甲基氯硅烷、二甲基二氯硅烷、甲基三氯硅烷、四氯化硅与甲基碘改性高硅MCM-41中孔分子筛。XRD,^2^9SiMASNMR,^1^3CMASNMR,以及N~2、水与环己烷吸附的表征,显示改性不同程度地改变了分子筛的表面组成与结构,减小孔径,增加孔壁厚度,因而影响吸附行为,减小吸附容量。硅烷化减少了MCM-41的表面硅羟基含量,增加其疏水性。用CH~3I改性使孔径减小1.4nm,而硅羟基含量并未显著减少。硅烷化以及用CH~3I改性可提高MCM-41分子筛的热稳定性。SiCl~4的改性作用相对不明显。样品的水及环己烷吸附容量与其表面硅羟基含量呈现不同的线性关系,揭示高硅MCM-41分子筛表面吸附中心的本性。     

木素磺酸盐用作表面活性剂驱油牺牲剂的研究

表面活性剂驱油是提高石油采收率最具潜力的技术之一。该技术成本昂贵的主要原因是地层岩石对表面活性剂的吸附而造成损失。使用牺牲剂来减少表面活性剂的吸附损失已有报道。本文研究了价格低廉的木素磺酸盐(LS)作为表面活性剂驱油牺牲剂的可行性。在同玉门油田表面活性剂体系配伍时,研究了改性 LS 的吸附特性,抗吸附损失作用及其对表面活性剂体系相行为的影响。结果表明,改性 LS 的吸附符合 Langmuir 方程;使用改性 LS 的水溶液对地层岩石进行预冲洗,可显著地减少表面活性剂的吸附损失(减少量>60%)。因为改性 LS 与阴离子表面活性剂有较好的协同作用,并可以提高其耐盐性。因此,改性 LS 作为表面活性剂驱油时的牺牲剂具有广阔的前景。     

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。     

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.     

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.     

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。     

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。     

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.