Solubility Measurements of Surfactants and Dissolution of Cytochrome c in 1,1,1,2‐Tetrafluoroethane Modified with Organic Solvents

The solubilities of four surfactants, sodium bis‐2‐ethylhexyl sulfosuccinate (AOT), cetyltrimethylammonium chloride, didodecyldimethylammonium bromide, and n‐dodecyltrimethylammonium chloride in liquid refrigerant 1,1,1,2‐tetrafluoroethane (R134a) modified with methanol, ethanol, and 2‐propanol were measured. The measurements were performed under 25 and 50 bar at 25 °C. The solubility of AOT was as high as 92 mM in R134a with addition of 2% ethanol. Cytochrome c molecules were then verified to be soluble in the AOT‐containing and ethanol‐modified R134a solution. Accordingly, liquid R134a is suggested as a potential extraction solvent for hydrophilic compounds.     

改性累托石吸附水溶液中苯酚的研究I吸附条件的确定

用十二烷基二甲基苄基氯化铵 (1227)、十六烷基三甲基溴化铵 (1631)、十八烷基三甲基溴化铵 (1831) 3种表面活性剂改性天然累托石 (REC) 粘土,分别得到3种有机改性累托石:1227-REC、1631-REC和1831-REC。用有机改性累托石作吸附剂,对水溶液中的苯酚进行吸附研究,考察了pH值、吸附时间、吸附剂用量、温度等因素对吸附效果的影响。结果发现,在本文研究条件下,3种吸附剂对苯酚达到较理想吸附效果的合理条件是:pH值分别为6、8、8;吸附平衡时间分别需要90、20、40min;吸附剂用量均为20g/L;常温。在确定的合理条件下,去除率分别能达到66.2%、99.0%、99.8%。     

两相催化体系中α，β－不饱和醛选择加氢反应研究Ⅲ．表面活性剂、溶剂对选择加氢反应的影响

研究了水溶性钌－膦配合物催化肉桂醛选择加氢反应中，相转移剂和表面活性剂对反应转化率和选择性的影响，考察了表面活性剂ＣＴＡＢ（十六烷基三甲溴化铵）浓度以及影响两相界面性质的因素—水相和有机相体积比、有机溶剂的改变等的影响．结果表明，相转移剂可以促进反应进行，其中以季铵盐相转移剂最好；表面活性剂能够显著地加快反应，其中以阳离子表面活性剂的效果最佳，且分子中含有长链烷基者（如ＣＴＡＢ）效果更好，非离子和阴离子表面活性剂的效果较差；对于ＣＴＡＢ，其浓度的增加导致反应速度的明显加快，但ＣＴＡＢ浓度达到１．６５×１０－２ｍｏｌ／Ｌ之后，反应体系乳化严重，反应完成后，两相分离变得困难．而增加水相体积和加入适当的有机溶剂，有利于转化率和选择性的提高．     

A study on the influence of anionic surfactants on electrochemical degradation of polyaniline

The influence of anionic surfactants on the electrochemical degradation of polyaniline (PANI), deposited by electro-polymerization onto platinum electrodes, was investigated in an aqueous medium by means of cyclic voltammetry. The degradation rate was found to be greatly dependent on the pH of the solution. The electrochemical degradation of PANI/dodecylsulfate and PANI/dodecylbenzenesulfonate films was compared with that of a PANI/hydrochloride film. The degradation rate in the two former cases decreased by some 50% compared to the PANI/hydrochloride film in aqueous solution at pH = 2. The results were confirmed with theoretical calculations performed on the evaluation of head group charge of surfactants, the distance of anions from PANI positive sites and the shielding of anions on PANI positive sites.     

Swelling behavior of amphiphilic hydrogels of copolymers of the vinyl ether of ethylene glycol and vinyl isobutyl ether,and their interaction with cationic surfactant

Amphiphilic hydrogels of copolymers of the vinyl ether of ethylene glycol and vinyl isobutyl ether were synthesized by -radiation-induced free radical polymerization. Hydrogels with certain copolymer compositions showed thermo-sensitive behavior in aqueous solutions. The swelling behavior of the hydrogels in cetylpyridinium bromide aqueous solution was studied. Increased swelling of the hydrogels was observed in the surfactant solutions. The increased swelling was more prominent for the hydrogels with a higher content of hydrophobic moiety in the copolymer composition, and with higher surfactant concentration. The reason for this phenomenon is discussed. Treatment of some hydrogels in the surfactant solutions resulted in higher swelling ability in distilled water with distinct thermo-induced contraction over a narrow temperature interval.     

Effect of surfactants on the stability of thin liquid film flow on a rotating disk

The effect of surfactants on surface instabilities of thin liquid film flow on a rotating disk was studied at different flow rates Q (0.5相似文献   

Reduction of soluble colloidal MnO<Subscript>2</Subscript> by <Emphasis Type="SmallCaps">DL</Emphasis>-malic acid in the absence and presence of nonionic TritonX-100

Kinetics of oxidation of DL-malic acid by water soluble colloidal MnO₂ (prepared from potassium permanganate and sodium thiosulfate solutions) have been studied spectrophotometrically in the absence and presence of nonionic Triton X-100 surfactant. The reaction is autocatalytic and manganese(II) (reduction product of the colloidal MnO₂) may be the autocatalyst. The order of the reaction is first in colloidal [MnO₂] as well as in [malic acid] both in the absence and presence of the surfactant. The reaction has acid-dependent and acid-independent paths and, in the former case, the order is fractional in [H⁺]. The effect of externally added manganese(II) is complex. The results show that the rate constant increases as the manganese(II) concentration is increased. It is not possible to predict the exact dependence of the rate constants on manganese(II) concentration, which has a series of reactions with other reactants. In the presence of TX-100, the observed effect on k is catalytic up to a certain [TX-100]; thereafter, an inhibitory effect follows. The catalytic effect is explained in terms of the mathematical model proposed by Tuncay et al. (in Colloids Surf A Physicochem Eng Aspects 149:279 3). Activation parameters associated with the observed rate constants (k_obs/k) have also been evaluated and discussed.     

表面活性剂在离子选择电极分析中的增敏作用

本文以涂丝Ag-Ag2S电极为指示电极,饱和甘汞电极和自制锑电极为参比电极,分别试验了加入阳离子、阴离子和非离子表面活性剂对电极灵敏度的影响。结果表明,加入非离子表面活性剂对电极响应无明显影响,但阴离子和阳离子表面活性剂可使电极灵敏度有较大提高;其中,十六烷基三甲基溴化铵(CTMAB)和十二烷基苯磺酸钠(SDBS)、十二烷基硫酸钠(SDS)对电极的增敏效果显著,可使电极响应线性范围下限扩大一个数量级左右,且电极响应时间缩短,稳定性提高。     

核糖核酸酶A在DAB-环乙烷溶液中的活性和构象

The activity and conformation of ribonuclerse A (RNaseA) solubilized in cyclohexane via dodecylammonium butyrate(DAB) reverse micelles were investigated. The activity of RNaseA was studied using the cytidine 2’,3’ -phosphate as the substrate, and it was found that kcat increases significantly with respect to that in water attended by an increased Km•FT-IR spectra of RNaseA in reverse micellar solution were investigated as a function of w0(= [H2O]/ [DAB]), and it was noted that the structure of RNaseA became losser in reverse micelles campared to that in aqueous solution. The relation between activity and conformation was discussed.     

动态单滴法研究乳状液液膜的稳定性

乳状液液膜作为化学分离的一种手段,自七十年代发现以来已有了许多进展,但是如何将其工业化还有许多课题有待于进一步研究.目前,除了乳状液液膜的水静态渗透性质以外,对乳状液液膜的稳定性和溶胀性质的研究主要采用搅拌法.虽然得到较好的规律性,但是搅拌法具有乳状液滴粒径分布广的弱点,对于不同的搅拌方式及条件,乳状液液膜的有效面积不同,对液膜作用的机械强度不同,因此结果会有很大差别.我们自行设计的动态单滴法实验装置,可定量地研究乳状液液膜的溶胀、稳定性及水渗透性质.