若干液体混合物的粘度和密度测定

本文用比重管和毛细管粘度计测定了乙酸乙酯-四氯化碳-环己烷-苯、甲醇-乙醇-异丙醇-四氯化碳、水-甲醇-乙醇-异丙醇、水-甲醇-丙酮-醋酸四个四元体系及包含的二元、三元体系在298.15K的密度和粘度。     

以乙二醇为萃取剂分离多种共沸物系的研究

本文以丙酮-甲醇、环己烷-异丙醇、异丙醇-水、乙醇-甲苯这4个常见共沸体系为研究对象,运用化工模拟软件Aspen Plus中的Analysis功能,考察乙二醇的加入对相对挥发度和气液平衡关系的影响,考察乙二醇是否为优良的萃取剂。     

降低甜菜碱表面活性剂中钠盐含量的研究

以环氧氯丙烷和亚硫酸氢钠、十二烷基二甲基胺为原料合成十二烷基二甲基羟丙基磺基甜菜碱,对产物进行分离,并检测其酸值、硫酸盐灰分含量、游离胺含量、季胺盐含量、活性物含量、氯化钠含量等指标。研究了乙醇-甲醇、甲醇-丙酮、乙醇-丙酮三种溶剂体系对降低十二烷基二甲基羟丙基磺基甜菜碱中氯化钠盐含量的影响,结果表明,当采用乙醇-丙酮体系时,V（乙醇）∶V（丙酮）=2∶7的除盐效果最佳,可使产品中氯化钠含量由原来的13.60%降至1.23%。     

苦豆子生物碱单体的分离纯化工艺研究

在对苦豆子的酸水浸提液进行了超滤和脱色预分离的基础上,采用不同的有机溶剂萃取和硅胶柱层析对其中主要的生物碱进行分离纯化及条件优化.结果表明合适的生物碱萃取富集条件是用氯仿为溶剂,Ph=10.5.该氯仿萃取液用硅胶柱层析分离,洗脱剂为氯仿-甲醇-氨水(5:0.4:0.01,V/V/V),洗脱速度1柱床体积·h-1,得到峰1～峰3.峰1和峰2中的化合物经丙酮结晶和重结晶分别得到纯度99%以上的氧化槐果碱和氧化苦参碱;峰3对应的组分再经硅胶柱层析,洗脱剂为丙酮-甲醇(10:1,V/V),洗脱速度1柱床体积·h-1,得到峰4～峰6,峰4中的化合物经石油醚结晶和重结晶,可以得到纯度95.8%的槐定碱.采用了HPLC-MS,IR,熔点测定和薄层色谱等方法进行上述生物碱单体的定性定量及分子结构确定. 本研究为深度开发苦豆子生物碱资源和为制备医药工业所需的高纯度生物碱原料提供了依据.     

2,4-二氨基-6-乙烯基三嗪

[性状] 2,4-二氨基-6-乙烯基三嗪(简称V.T.)为近中性的白色结晶粉末,熔点239～241℃,可溶于热水和热的酯、酸中,但不溶于热的甲醇、乙醇或丙酮。 V.T.在热水中用偶氮二异丁腈引发可聚合成难溶于水的聚合物,可与丙烯腈等单体很好地共聚,在其它高分子链中引入适量     

美伐他汀结晶纯化工艺研究

目的:分析并总结优化美伐他汀提取工艺.方法:以相同质量美伐他汀粗品为原料,采用丙酮、乙酸乙酯、乙醇和异丙醇4种溶剂结晶.结果:脱水美伐杂质去除效果顺序为乙酸乙酯>丙酮>乙醇>异丙醇;双氢美伐杂质去除效果顺序为异丙醇>乙醇>乙酸乙酯>丙酮;低温浸泡(≤5℃)去除蛋白效果较好.结论:综合考虑应选择异丙醇溶剂作为结晶溶剂;在...     

氢溴酸右美沙芬残留溶剂测定方法研究

建立顶空毛细管气相色谱法测定氢溴酸右美沙芬中残留溶剂。方法:采用毛细管气相色谱法:氢火焰离子化检测器(FID);载气为氮气;采用DB-624色谱柱(30m×0.32mm,膜厚1.8um,固定液:6%氰丙基苯基-94%二甲基聚硅氧烷)毛细管石英柱;程序升温。结果:甲醇、乙醇、异丙醇、丙酮和甲苯均能得到有效分离,各组分均有良好线性关系(r≥0.995);检测限为甲醇:14ppm、乙醇:13ppm、异丙醇:8.8ppm、丙酮:7.5ppm、甲苯:0.95ppm。回收率标准为80.0%-120.0%(RSD≤10%),其中甲醇平均为:88.59%(RSD=4.06%),乙醇:91.63%(RSD=4.93%),异丙醇:94.04%(RSD=3.10%),丙酮:90.85%(RSD=3.18%),甲苯为:97.89%(RSD=9.72%)。结论:该方法灵敏,准确可靠,可用于氢溴酸右美沙芬中残留溶剂的检测。     

聚氨酯相转化法成膜的性能及其分形描述

采用液-液相转换法通过不同的非溶剂(水、甲醇、乙醇和异丙醇)制备聚氨酯微孔膜,测定了膜的断面形态、孔隙率、孔径、透气性和力学性能。结果表明:聚氨酯膜较容易在醇类非溶剂中形成均一形貌的多孔结构,4种非溶剂所制备聚氨酯膜的孔径由大到小的顺序依次为水、甲醇、异丙醇和乙醇,透气性从大到小的顺序依次是甲醇、异丙醇、乙醇和水,拉伸强度和断裂伸长率从大到小的顺序依次是乙醇、异丙醇、甲醇和水。用分形数学定量表示微孔结构,发现按分形模型计算出的结果与实验测试结果相符。     

7-氯喹哪啶加合物在分离中的应用研究

通过静态重量法测量7-氯喹哪啶、7-氯喹哪啶L-酒石酸盐或7-氯喹哪啶对硝基邻苯二甲酸酯在甲醇、 乙醇、 正丙醇、异丙醇、正丁醇、异丁醇和丙酮中的平衡溶解度,结果表明:7-氯喹哪啶、7-氯喹哪啶酒石酸盐、7-氯喹哪啶对硝基邻苯二甲酸酯在七种溶剂中的溶解度有较明显的差异.利用改进的阿佩尔布拉反应式相关联,均方根偏差(RM...     

异烟肼在有机溶剂中溶解度测定及晶习研究

在283.15~323.25 K范围内,利用在线浊度法测定了异烟肼在甲醇、乙醇、正丙醇、异丙醇、正丁醇、异丁醇、丙酮、乙腈、乙酸甲酯与乙酸丁酯中的溶解度。数据表明,异烟肼在不同溶剂中的溶解度均随着温度升高而增加。在同一温度下,异烟肼的溶解度与溶剂关系符合如下顺序：甲醇 > 丙酮 > 乙醇 > 正丙醇 > 异丙醇 > 乙酸甲酯 > 异丁醇 > 正丁醇 > 乙腈 > 乙酸丁酯。采用改进的Apelblat、Wilson与NRTL方程对溶解度数据进行了拟合,结果与实验数据有较高的吻合。基于溶解度数据,对异烟肼溶解焓、溶解熵与溶解吉布斯能进行了计算,发现异烟肼溶解过程是吸热熵增过程。分析了甲醇、乙醇、正丙醇与丙酮对异烟肼冷却结晶过程所获产品晶习的影响,确定乙醇为合适的结晶溶剂。     

Electrooxidation of Methanol and Ethylene Glycol Mixture on Platinum and Palladium in Alkaline Medium

The performance of mixture of methanol and ethylene glycol (EG) oxidation has been studied on both Pt and Pd electrodes in alkaline medium. The activity of EG oxidation is better than that of methanol oxidation and the stability of EG oxidation is better than that of methanol and ethanol oxidation on the Pd electrode. The onset potential for ethanol oxidation is more negative 200 mV than that of EG, however the stability of EG oxidation on the Pd electrode is better than that of ethanol oxidation. The performance of methanol oxidation improves pronouncedly by adding a small amount of EG on both Pt and Pd electrodes. The onset potential and peak potential of mixture of methanol and EG oxidation are close to or more negative than that of sole methanol and EG oxidation on the Pd electrode. The mixture of methanol and EG is more easily to be electrochemically oxidized and gives a better performance than sole methanol and EG on the Pd electrode. The results show that the mixture of methanol and EG is a promising candidate as fuel in direct alcohol fuel cells.     

A remarkable activity of glycerol electrooxidation on gold in alkaline medium

In this paper, the activity and stability of glycerol oxidation on Au electrode have been investigated by cyclic voltametry, chronoamperometry and chronopotentiometry methods in alkaline medium. The glycerol shows a remarkable activity and better performance than methanol, ethanol, n-propanol, isopropanol and ethylene glycol on the Au electrode in alkaline medium. The activity and stability of glycerol oxidation on the Au electrode are higher than that of glycerol oxidation on Pd electrode. The stability of glycerol oxidation on the Au electrode is higher than that of methanol and glycerol oxidation on Pt electrode. The results show that glycerol is an excellent fuel applied in direct alcohol fuel cells with Au as anode catalyst.     

Electrochemical investigation of Pd nanoparticles and MWCNTs supported Pd nanoparticles-coated electrodes for alcohols (C1–C3) oxidation in fuel cells

Incorporation of palladium nanoparticles (PdNPs) and multi-walled carbon nanotubes (MWCNTs) into chitosan-coated glassy carbon (GC) electrode for alcohols (methanol, ethanol, and isopropanol) electrooxidation has been studied. PdNPs–chitosan and MWCNTs–PdNPs–chitosan nanocomposites are successfully prepared and characterized by transmission electron microscopy images and UV–Vis spectroscopy. Based on the results, PdNPs–chitosan nanocomposite indicates high electrochemical activity and excellent catalytic characteristic for alcohol (C₁–C₃) electrooxidation on a GC electrode in an alkaline medium. The current density of the alcohols oxidation at GC–PdNPs–chitosan electrode is investigated in optimized conditions and compared with that obtained at the GC-modified electrode by Pd with different polymers. Also, our results show that the dispersion of Pd nanoparticles on the MWCNTs significantly improved the performance of the PdNPs/chitosan composite for electrooxidation of the C₁–C₃ alcohols.     

Calculation of alcohol‐acetone‐cellulose acetate ternary phase diagram and their relevance to membrane formation

ABSTRACT Alcohol‐acetone‐cellulose acetate phase diagrams incorporated with methanol, ethanol, and isopropanol as nonsolvents are calculated according to a new form of the Flory–Huggins equation. Nonsolvent–cellulose acetate interaction parameters are measured by swelling experiments. Concentration‐dependent nonsolvent–solvent interaction parameters are obtained by vapor–liquid equilibrium and the Wilson equation. It is shown that alcohol is a week coagulant compared with water, and water > methanol > ethanol > isopropanol for cellulose acetate. The phase diagrams characteristic of acetone‐cellulose acetate combined with water, methanol, ethanol, and isopropanol as nonsolvents is different, which leads to the different morphological structure of a cellulose acetate membrane. The structure of a water coagulated membrane has large macrovoids from liquid–liquid phase separation. A methanol coagulated membrane has a honeycomb‐like structure from spinodal microphase separation. An ethanol or isopropanol coagulated membrane has a thicker, dense top layer from the delay time phase separation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1650–1657, 2001     

Water-Gas Shift Reaction in a Microchannel Ni-based Catalytic Coated Reactor: Effect of Solvents

Medium-temperature shift (MTS) reaction was investigated in a microchannel reactor using the electrophoretic deposition (EPD) method to coat porous layers of Ni-K/CeO₂ catalyst on stainless-steel plates. The electrolyte suspensions of the catalyst were prepared in isopropanol, ethanol, methanol, and acetone as solvents. All EPD experiments were carried out under similar conditions (i.e., for a contact time of 3 min, at a voltage of 140 V, and in the presence of 0.3 wt % polyethylenimine as the dispersant). The effect of the different solvents on the coated catalytic layers was studied using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and 2D and 3D optical imaging. The experimental results proved that the best performance for the MTS reaction in the plate microreactor was achieved with isopropanol as the solvent.     

Optimization of Carboxymethylation of Starch in Organic Solvents

A comparative study of the influence of ethanol, benzene, acetone, isopropanol, and mixtures of ethanol-acetone, ethanol-benzene, and ethanol-isopropanol as slurry media on the degree of substitution and viscosity of carboxymethyl starch during carboxymethylation is presented. It is shown that the degree of substitution increases with increasing acetone, isopropanol, or benzene content in the mixed solvent. After the same carboxymethylation steps the degree of substitution with ethanol/benzene mixture is higher than that with ethanol/isopropanol mixture.     

羧甲基羟丙基瓜尔胶合成新工艺及性能

为解决羧甲基羟丙基瓜尔胶(CMHPG)合成过程中副产物多,容易糊化的问题.以丙酮为反应介质,甲醇钠为催化剂代替乙醇、异丙醇为介质,氢氧化钠为催化剂.探讨了工艺条件对产品的影响,找出了较佳工艺条件.结果表明,合成较佳工艺条件为:环氧丙烷与瓜尔胶质量比为0.2∶1、氯乙酸与瓜尔胶质量比为0.4∶1,反应时间为160 min;前者催化剂与瓜尔胶质量比为0.2∶1、反应温度为45～50℃,后者催化剂与瓜尔胶质量比为0.3∶1,反应温度为65～ 70℃.乙醇、异丙醇为介质,氢氧化钠为催化剂合成产品的羧甲基取代度为0.43,羟丙基取代度为0.36,粘度为1 120mPa·s;以丙酮为反应介质,甲醇钠为催化剂合成产品羧甲基取代度为0.48,羟丙基取代度为0.37,粘度为1 030 mPa·s.     

Pd/Ni/Si-microchannel-plate-based amperometric sensor for ethanol detection

A sensitive amperometric ethanol sensor composed of highly dispersed palladium nanoparticles on a vertically aligned nickel-coated silicon microchannel plate (MCP) has been constructed. The morphology of the palladium-modified nickel-coated silicon MCP electrode was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The performance of the Pd/Ni/Si MCP electrode for the electrochemical detection of ethanol was investigated by cyclic voltammetry and amperometry. The electrode with three-dimensional structure shows high-catalytic activity towards the oxidation of ethanol in a 0.10 M KOH solution. At an applied potential of −0.10 V, the Pd/Ni/Si MCP electrode presents a high sensitivity of 0.992 mA mM⁻¹ cm⁻², and the detection limit is 16.8 μM. The linear range is up to 60 mM with a linear correlation coefficient of 0.998. The Pd/Ni/Si MCP electrode also possesses excellent electrocatalytic properties, rapid response, and good stability and repeatability. This novel electrode has great potential in the accurate and effective detection of ethanol.     

低碳醇对氟碳与碳氢表面活性剂复配体系泡沫性能的影响

普通碳氢表面活性剂与磺基甜菜碱氟碳表面活性剂(FS)相比,泡沫性能和耐油性不好。醇通常强烈地影响表面活性剂的自组织行为,醇的加入能提高表面活性剂的泡沫性能。本文采用Ross-Miles法探讨了低碳醇对FS与阴离子碳氢表面活性剂(AOS)复配体系FS/AOS泡沫性能的影响。结果表明,当甲醇、无水乙醇、异丙醇浓度分别为5%、3%、3%,复配体系FS/AOS的起泡性能和泡沫稳定性仍较好,在加入醇之后,煤油含量60%～80%时起泡性能和泡沫稳定性仍较好。不同碳数的低碳醇对复配体系泡沫性能的影响规律为:发泡性能甲醇最好、异丙醇次之、无水乙醇最差,异丙醇的稳泡性能较甲醇和无水乙醇差。