在丙酮-水溶液中研究硫氰酸钼(Ⅴ)络合物的萃取行为

本文用分光光度法研究了在不同浓度的丙酮－水溶液中硫氰酸钼（Ⅴ）络合物，以石油亚砜（PSO）－三氯甲烷（CHCl3)萃取剂的萃取行为，由分光光度数据直接计算萃取分配比，讨论了分配比与混合溶液中硫氰酸根浓度的函数关系，研究了丙酮在混合溶液中体积百分数的增加对分配比和萃取百分率的影响，并对实验结果进行了解释，实验表明，MoO(SCN)3萃取体积有应用价值。     

二(2-乙基己基)磷酸络合萃取对氨基苯酚

二 (2 -乙基己基 )磷酸 (D2 EHPA)络合萃取对氨基苯酚 (PAP)。研究了稀释剂种类、溶液的初始 p H值等因素对稀溶液分配比 (D)的影响。溶液的初始 p H值 (p H2— 1 1 )对萃取结果影响较大 ,当初始 p H值在p Ka1 和 p Ka2 之间时 ,分配比出现峰值。稀释剂则主要是通过物理萃取实现。在同一浓度下 ,二 (2 -乙基己基 )磷酸的萃取能力随稀释剂的极性增大而提高 ,极性环境明显优于惰性稀释剂环境。红外光谱分析表明 ,络合萃取过程存在离子交换和离子缔合两种反应机制。     

混合溶液折射率对局域表面等离子体共振的影响

对水-二甲基亚砜二元混合溶液质量分数和温度与折射率的关系进行了理论和实验研究,对几种经典模型的拟合结果进行了比较,给出了适合水-二甲基亚砜混合溶液的经验公式。对水性金溶胶-二甲基亚砜混合溶液质量分数和温度对局域表面等离子体共振峰值波长的影响进行了理论和实验研究,结果表明:水性金溶胶-二甲基亚砜混合溶液质量分数对共振峰值波长的调节有较好的线性关系和较大的调节范围,当温度从20 ℃增大到60 ℃,混合溶液金溶胶的共振峰值波长增加了1367 pm,温度敏感度为34 pm/K,在0%~100%的质量分数范围内,混合溶液金溶胶的共振峰值波长平均产生8.5103 pm的增长。     

在丙酮-水不同配比的溶剂中对硫氰酸钼(Ⅴ)络合物的光度法研究

在不同体积配比的丙酮－水混合溶剂中,存在不同浓度硫氰酸根时,测定了硫氰酸钼（Ⅴ）络合物的各级摩尔吸光系数和稳定常数及各级络离子的百分组成。结果表明,上述各项都随着体系中丙酮浓度的增加而不断增大。     

Tween-80胶束萃取硫氰酸钼(Ⅴ)配合物研究

本文研究了用Tween-80作萃取剂取硫氰酸钼（Ⅴ），在0.1%浓度下即可达到94％的萃取率，而同样条件下对硫氰酸钨（Ⅲ）基本不萃取，因此可将二者很好的分离。其萃取机理可能为胶束萃取，属超分子范畴。     

在丙酮—水不同配比的溶剂中对硫氰酸钼（Ⅴ）络合物的光度法测定

在不同体积配比的丙酮－水混合溶剂中，存在不同浓度硫氰酸根时，测定了硫氰酸钼络合物的各级摩尔吸光系数和稳定常数及各级络离子的百分组成。结果表明，上述各项随着体系中丙酮浓度的增加而不断增大。     

浊点萃取-分光光度法测定水样中微量钒

提出了以5-Br-PADAP为络合剂、Triton X-114为表面活性剂的浊点萃取-分光光度法测定微量钒的新方法.探讨了溶液pH值,试剂浓度和平衡温度等实验条件对浊点萃取及测定灵敏度的影响.在优化的实验条件下,富集50mL样品溶液,钒的检出限为0.099 μg·mL-1,富集倍率为45.6.方法用于水样中测定微量钒的测定,结果满意.     

轻质萃取剂的分散液液微萃取-石墨炉原子吸收光谱法测定生活用水中痕量Pb与Cd

以轻质溶剂辛醇为萃取剂,建立了分散液液微萃取-石墨炉原子吸收光谱分析法(LDS-DLLME-GFAAS),并应用于生活用水中痕量Pb及Cd的测定。在分散液液微萃取(DLLME)中,以二乙基二硫代氨基甲酸盐(DDTC)为螯合剂,用微量注射器将辛醇和甲醇的混合溶液快速注入到样品溶液中发生雾化分散现象,Pb2+和Cd2+与DDTC的络合物被萃取到辛醇微滴中。离心分离后,以GFAAS测定萃取至上层辛醇相中的分析物。实验考察了萃取剂种类和体积、分散剂种类和体积、pH、DDTC浓度、萃取时间等影响萃取效率的实验参数。在最优实验条件下,Pb和Cd的检出限分别为0.15和0.03 μg·L-1,富集倍数分别为87和48,具有良好的线性和精密度。该分析方法优势在于操作简便,快速,低成本,高富集倍数,萃取剂用量少,已成功应用于自来水、饮用水和南湖水中痕量Pb和Cd的检测。     

浊点萃取-分光光度法测定彩笔中的灿烂绿

建立了浊点萃取-分光光度法测定灿烂绿的方法.以非离子型表面活性剂Triton X-114为萃取剂,富集、分离灿烂绿,采用分光光度法进行检测.研究了缓冲溶液用量、表面活性剂用量、平衡温度和平衡时间对浊点萃取的影响,得到最佳实验条件：5％的Triton X-114溶液2.5mL、pH3.8的盐酸-柠檬酸钠缓冲溶液2.0mL、平衡温度和时间分别为50℃和15min.在优化的实验条件下,灿烂绿被萃取到Triton X-114相与水相分离.该方法用于彩笔中灿烂绿的测定,结果满意.     

分光光度法测定聚维酮碘中的碘

建立分光光度法测定聚维酮碘溶液中碘含量的方法。在酸性条件下,利用过氧化氢溶液将聚维酮碘溶液中结合碘转化为游离碘,用二氯甲烷萃取碘,采用分光光度法进行含量测定,碘的二氯甲烷溶液在504nm处有最大吸收,有效碘浓度在0.0001—0.002mol·L-1范围内线性关系良好(r=0.9995),平均回收率(n=9)为99.48%。该方法操作简便,结果准确,重现性好,可用于聚维酮碘溶液的质量控制。     

Braking of the dimethyl sulfoxide molecule rotation during poly(acrylonitrile) dissolution

The variation of the dimethyl sulfoxide molecule rotational speed with addition of poly(acrylonitrile) is studied using Raman spectroscopy and photoluminescence spectroscopy. It is found that there is a “critical” concentration of poly(acrylonitrile) at which the rotation of dimethyl sulfoxide molecules is braked. At such a concentration of poly(acrylonitrile), the mean distance between its molecules is close to the length of dimethyl sulfoxide molecules and arising steric obstacles brake the rotation of dimethyl sulfoxide molecules.     

钙钛矿薄膜的微结构和光电特性优化

分别以纯二甲基甲酰胺、纯二甲基亚砜以及二者不同比例的混合物作为前驱体溶剂,制备钙钛矿薄膜样品.将薄膜样品分为两组,分别将其置于氮气氛围中进行热退火和二甲基亚砜蒸汽氛围中进行溶剂退火,并对薄膜样品的微观结构和光电特性进行系统研究分析.结果表明,与热退火相比,经溶剂退火后样品的平均晶粒尺寸和均匀性显著提升,从而减小了薄膜中晶粒边界或界面的体积分数.采用混合前驱体溶剂和后续溶剂退火增加了薄膜的厚度和可见光的利用率,有效改善了薄膜形貌,优化了结晶质量.同时薄膜光致发光强度的增加,表明薄膜缺陷态密度降低.采用优化后的钙钛矿薄膜作为吸收层制备太阳电池,其光电转换效率达到15.7%.     

Some thermodynamic processes of anthracite–carbon dioxide mixture in supercritical fluid state

In the context of the development of the catalyst regeneration procedure via supercritical fluid CO₂ extraction, some thermodynamic properties of the anthracene–carbon dioxide mixture in supercritical fluid state have been studied. Data on anthracene solubility in pure and modified (dimethyl sulfoxide, 5 wt %) supercritical carbon dioxide (SC–CO₂), the heat capacity of anthracene and its mixtures with carbon dioxide, and the heat of solution of anthracene in SC–CO₂ are presented. Anthracene solubility in SC–CO₂ is described satisfactorily using the Peng–Robinson equation of state.     

Investigation of hydrogen bonding in neat dimethyl sulfoxide and binary mixture (dimethyl sulfoxide + water) by concentration-dependent Raman study and ab initio calculation

In this study,our vibrational spectroscopic analysis is made on hydrogen-bonding between dimethyl sulfoxide and water comprises both experimental Raman spectra and ab initio calculations on structures of various dimethyl sulfoxide/water clusters with increasing water content.The Raman peak position of the v(S=O) stretching mode of dimethyl sulfoxide serves as a probe for monitoring the degree of hydrogen-bonding between dimethyl sulfoxide and water.In addition,the two vibrational modes,namely,the CH 3 symmetric stretching mode and the CH 3 asymmetric stretching mode have been analysed under different concentrations.We relate the computational results to the experimental vibrational wavenumber trends that are observed in our concentration-dependent Raman study.The combination of experimental Raman data with ab initio calculation leads to a better knowledge of the nature of the hydrogen bonding and the structures of the hydrogen-bonded complexes studied.     

Regeneration of the active aluminum oxide catalyst in supercritical carbon dioxide

The nature of the compounds inactivating the active aluminum oxide catalyst is studied. The results of the catalyst regeneration by pure supercritical carbon dioxide and by the supercritical carbon dioxide modified with a polar additive (2 wt % dimethyl sulfoxide) are presented.     

Sonocatalytic degradation of methylene blue with TiO2 pellets in water

A series of experiments were carried out to study the degradation of methylene blue by the irradiation of ultrasound onto TiO(2) in aqueous solution. A statistically significant decrease in the concentration of methylene blue was observed after 60 min irradiation. While the reduction was 22% of the initial concentration without H(2)O(2), addition of H(2)O(2) significantly enhanced the degradation of methylene blue for the TiO(2) containing system (85% reduction of the initial concentration). The addition of H(2)O(2) had no effect on the methylene blue degradation when the system contained Al(2)O(3). The degradation ratio of methylene blue was dependent on the amount of TiO(2) and also the specific surface area of TiO(2) in the solution. The effects of radical scavenging agents on the degradation of methylene blue were also investigated for the system with TiO(2). It was found that the radical scavenging agents dimethyl sulfoxide (DMSO), methanol, and mannitol suppressed the degradation, with DMSO being the most effective. The effect of pH on the degradation of methylene blue was further investigated. An U-shaped change in the concentration of methylene blue in the presence of TiO(2) was observed along with the change in pH values (pH 3-12), and the highest degradation ratio was observed at around pH 7. In conclusion, ultrasound irradiation of TiO(2) in aqueous solution resulted in significant generation of hydroxyl radicals, and this process may have potential for the treatment of organic dyes in wastewater.     

Conductivity of solutions of poly(acrylonitrile) in dimethyl sulfoxide

The conductivity of solutions of poly(acrylonitrile) (PAN) in dimethyl sulfoxide (DMSO) is studied. Using the Raman spectroscopy method, it is found that PAN causes associates of DMSO molecules to dissociate into free molecules, as a result of which the conductivity of the solution grows. Simultaneously, PAN molecules hamper the rotation of DMSO molecules, which decreases the conductivity. There exists a critical concentration of PAN (≈5.4 vol. %) at which the rotation of DMSO molecules is hindered to the greatest extent and the conductivity drops by an order of magnitude.     

A convenient method to remove ruthenium byproducts from olefin metathesis reactions using polymer-bound triphenylphosphine oxide (TPPO)

Summary Ruthenium byproducts from ring-closing metathesis reactions can be removed by refluxing the crude reaction mixture with resin-bound triphenylphosphine oxide (TPPO) in toluene or by stirring with dimethyl sulfoxide (DMSO) and silica gel at room temperature. Residual levels of ruthenium can be achieved that are as low as 0.04 μg per 5 mg of product when a combination of TPPO, DMSO, and silica gel is used. The polymer-bound TPPO retained its efficiency after being recycled six times.     

Tautomerism in Chlorinated O-Hydroxyschiff Bases: Effect of Chlorine Atom Substitution

The UV spectra of some chlorinated o-hydroxyschiff bases were studied in different solvents. It was found that schiff bases derived from condensation of 2-hydroxybenzaldehyde or 5-chloro-2-hydroxy benzaldehyde with substituted aniline exist as enol form, whereas schiff bases derived from the condensation of 3,5-dichloro-2-hydroxybenzaldehyde with substituted aniline exist as enol form, whereas schiff bases derived from the condensation of 3,5-dichloro-2-hydroxybenzaldehyde with aniline exist as keto form especially in dimethyl sulfoxide. The ratio of enol/keto isomers were calculated for these schiff bases.