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用紫外-可见吸收光谱和荧光发射光谱研究了蒽在不同组成和结构的十二烷基硫酸钠(SDS)/苯甲醇(BA)/H20微乳液中的光谱特征,探讨了微乳液组成和结构对蒽光谱特征的影响,阐述了蒽在微乳液中的定位。结果表明,蒽位于O/W微乳液的膜相和油核;在SDS/BA/H2O W/O微乳液中,蒽定位于油连续相。 相似文献
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GUO Xia XU Hui GUO Rong ** Department of Chemistry Yangzhou University Yangzhou P. R. China 《高等学校化学研究》2003,19(4):484-488
IntroductionDuring the last decade,microemulsions haveplayed important roles in the development of bio-logical,material,environmental and other relatedfields[1— 4] .Although photo- induced electron trans-fer processes are of considerable interest in biologyand chemistry,up to now,most of the studies ofthe photo- induced electron transfer in micelle andinverse micelle have been limited to one- or two-component water/surfactant systems[5] .As theirextensions to microemulsion,only a very limited… 相似文献
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Photoinduced electron-transfer reaction of anthracene with N,N-diethylaniline (DEA) was studied in the SDS (sodium dodecyl sulfate)/BA (benzyl alcohol)/H2O system. In an oil/water microemulsion, only the excited anthracene located at the interface can be quenched by DEA. In a water/oil microemulsion, this quenching reaction occurs in the BA continuous phase. Besides being the quencher of the excited anthracene, DEA could also change the system's structure. 相似文献
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Photoisomerization of trans-stilbene (TS) was investigated in sodium dodecyl sulfate (SDS)/benzyl alcohol (BA)/H(2)O systems in order to establish the relationship between the reaction yields and the compositions and structures of molecular organized assemblies. The results show that, in SDS/BA/H(2)O systems with the structures of oil in water microemulsions, bicontinuous microemulsions, and hexagonal liquid crystals, the reaction yields are much larger than those in benzyl alcohol, both with and without the photosensitizer 9,10-anthracenedicarbonitrile. However, SDS/BA/H(2)O water in oil microemulsion and lamellar liquid crystal can obviously catalyze the photoisomerization of TS only when the photosensitizer is not present. The yield is increased with the increase in H(2)O content or with the decrease in BA content. 相似文献
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The influence of L-tryptophan (L-Trp) on the interphase electric properties of sodium dodecyl sulfate (SDS)/n-pentanol (n-C(5)H(11)OH)/water (H(2)O) system was studied by the method of AC impedance, and the distribution of L-Trp between the microemulsion phases with different structures in SDS/n-C(5)H(11)OH/H(2)O system was determined by UV-vis spectroscopy. The results show that L-Trp transfers from the lower phase (O/W or bicontinuous) to the upper phase (W/O), and that a small amount of SDS transfers from the upper phase to the lower phase correspondingly with the increase of the total SDS content at a constant weight ratio of n-C(5)H(11)OH/H(2)O=50/50 and a total L-Trp concentration of 1.0 x 10(-4) mol/L. In addition, the concentrations of L-Trp in both the upper and lower phases increase, but the SDS content decreases slightly in the upper phase and increases appreciably in the lower phase with the increase of the total L-Trp concentration at a constant total content of SDS. The interphase capacitance and the interphase charge-transfer current of the system increase, but the interphase resistivity decreases. 相似文献
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MU Jian-hai ZHAO Kong-shuang ** WEI Su-xiang LI Ying LI Gan-zuo . Key Laboratory for Colloid & Interface Chemistry of State Education Ministry Shandong Uinversity Jinan P. R. China . Department of Chemistry Beijing Normal University Beijing P. R. China . Department of Chemistry South China Normal University Guangzhou P. R. China 《高等学校化学研究》2004,20(1):92-98
IntroductionDielectricrelaxationspectroscopy(DRS) possess esanimportantpositioninmodern physicochemicalanalysis .Dielectricmeasurementscanbedoneinsuchawidefrequencyrangeof 10 - 5— 10 11Hz ,makingitpossibletodetectallkindsofprocessesofvarioussys tems[1] .DRSisbasedonthepolarizationtheory ,in cludingdipolereorientation polarization ,interfacialpolarization ,ionicpolarizationandelectronicpolariza tion ,ofwhichinterfacialpolarizationis prevalent.Whenthereexistsaclearphaseinterface ,aninterfa c… 相似文献
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LIZhong-chun LIUTian-qing GUORong 《高等学校化学研究》2005,21(3):322-325
The electrochemical oxidation of L-cysteine in an SDS/BA/H2O microemulsion system was studied with the methods of ultramicroelectrode cyclic voltammetry and AC impedance. The catalytic efficiency of the microemulsion on the electrochemical oxidation increases with the increase of BA or SDS content, but decreases with the increase of the water content because of the effects of BA, SDS and water on the solubilization of Lcysteine in the microemulsion. Furthermore, the catalytic efficiency of the bicontinuous structure is greater than that of an O/W microemulsion system. The results derived from both the rate constant k^0 and Gibbs free energy △G^≠ accord with those from the catalytic efficiency. 相似文献
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Photoinduced electron-transfer system of anthracene-N,N-di-ethylaniline (DEA) was studied in the oil in water (O/W) mi-croemulsions formed by SDS (sodium dodecyl sulfate),BA (benzyl alcohol) and H2O.The time-resolved fluorescence study showed that the fluorescence quenching of the excited anthracene by DEA occurs at the interface of the O/W mi-croemulsions.Besides as the quencher of the excited anthracene,N,N-diethylaniline could act as a cosurfactant to change the structures of the microemulsions,just as BA did.The quenching rate constants for the different structures of the system were determined. 相似文献
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IntroductionMicellesolutioncomposedofsurfactantscanaffect,adjustandcontrolmanychemicalreactionsaccordingtoitseffectsoflocalconcentration ,polarity ,charge ,microvis cosity,electrostatics ,etc ..1,2 Recently ,ithasarousedmuchattentiontoconductchemicalreactionsusingmi croemulsionasmicroreactor .3 7Theeffectofmicelleonthechemicalreactionstemsfromitsstaticelectricityandhy drophobicity .Usually ,cationicsurfactantcancatalyzethereactionbetweennucleophileandneutralmolecule ,whileanionicsurfactantsusp… 相似文献
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阴离子型微乳液的电导行为及其溶液结构 总被引:14,自引:0,他引:14
根据电导测量,研究了属于W/O→双连续→O/W一类微乳液的十二烷基硫酸钠(SDS)/正丁醇/辛烷/水体系的溶液结构.并探讨了表面活性剂离子对微乳液导电行为的贡献,以及表面活性剂与助表面活性剂含量、油含量对微乳液溶液结构的影响.微乳液的导电行为在W/O子区域中主要是由于SDS阴离子和在O/W子区域中是由于Na离子的影响.在双连续区(IZ)中SDS阴离子和Na阳离子都能影响导电行为增加表面活性剂含量有助于形成O/W微乳液,而助表面活性剂和油含量都增加有助于于形成W/O微乳液. 相似文献
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XiaGUO LingLIN RongGUO 《中国化学快报》2004,15(6):691-694
The photoisomerization of trans-stilbene was studied in the water in oil (W/O) microemulsion formed by SDS (sodium dodeeyl sulfate), n-C5H11OH (1-pentanol) and H2O. The experimental results show that after 2-minute UV-irradiation, the yield of cis-stilbene is higher in W/O mieroemulsion than in homogeneous solvent-n-C5H11OH. 相似文献
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拟三元相图的研究可为获得制备纳米材料的微乳液提供理论依据。本文首先通过实验绘制了45℃下十二烷基硫酸钠(SDS)/正戊醇-环己烷-水溶液体系的拟三元相图,并用电导法进行了验证,说明电导的测定结果与相图吻合的很好。其次,绘制了45℃及65℃下,SDS/正戊醇-环己烷-水、SDS/正戊醇-环己烷-硝酸锌水溶液和SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图并对6个相图进行了比较,研究了碱(NaOH)和盐(Zn(NO_3)_2)对SDS/正戊醇-环己烷-水拟三元体系相图影响。结果表明,硝酸锌及碱的加入使SDS/正戊醇-环己烷-水拟三元相图水包油(O/W)和油包水(W/O)区域明显的缩小。45℃时,SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图中的O/W区域甚至消失;65℃时,O/W和W/O区域均存在,且3个相图的W/O和O/W区域有重叠区。在此基础上,确定了制备纳米Zn O的微乳液的条件,即SDS/正戊醇-环己烷-硝酸锌水溶液和SDS/正戊醇-环己烷-氢氧化钠水溶液体系的拟三元相图中W/O区域的重叠区(各相图中的Ⅱ区)。制备的纳米氧化锌为多晶结构,平均粒径为80 nm。 相似文献
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十二烷基磺酸钠微乳状液结构转变的电化学研究 总被引:1,自引:0,他引:1
制备了C12H25SO3Na-C4H9OH-C7H16-H2O四组分体系在km=W(C4H9OH)/W(C12H25SO3Na)=2时的拟三元相图。使用二茂铁和铁氰化钾作为电化学探针用循环伏安法测定了起始含油量为21%的无水混合物在滴加水过程中所形成的微太液的扩散系数。从扩散系数随含水量的变化确定微乳液的结构转变。含水量为20%-45%时生成油包水型微液;含水量大于65%时生成水包油型微乳液。当含水量在45%-65%之间时形成的是二连续型微乳液。电导率数据证实了循环伏安法的测定结果。 相似文献
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测定了十二烷基磺酸钠(AS)/十六烷基三甲基溴化铵(CTAB)/正丁醇(n-C4H9OH)/正庚烷(n-C7H16)/水(H2O),十二烷基硫酸钠(SDS)/十六烷基三甲基溴化铵(CTAB)/正丁醇(n-C4H9OH)/正庚烷(n-C7H16)/水(H2O)体系的微乳液正四面体相图,并用电导法划分了AS/CTAB/n-C4H9OH/n-C7H16/H2O体系微乳液的结构(W/O,B.C.和O/W);同时研究AS/CTAB/n-C4H9OH/n-C7H16/H2O/盐类(NaCl,CaCl2或AlCl3)体系和SDS/CTAB/n-C4H9OH/n-C7H16/H2O/盐类(NaCl,CaCl2或AlCl3)体系形成中相微乳的盐宽,从中得出上述两体系中相微乳的盐宽随盐类阳离子价态的增大而的规律。 相似文献