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【期刊论文】Critical Behavior of a Pseudobinary System for a Three-Component Microemulsion
沈伟国, Xueqin An, * Jiao Feng, and Weiguo Shen
J. Phys. Chem. 1996, 100, 16674-16677,-0001,():
-1年11月30日
A three-component microemulsion system can be regarded as a pseudobinary mixture at certain conditions. The coexistence curves of (T, n), (T,φ), and (T, ψ) (n and are refractive index and volume fraction, respectively; ψ is defined as ψ=φ/[φ+φc(1-φ)/(1-φc)]) for a ternary microemulsion (AOT-waterdecane) at constant pressure and a constant ratio of water to AOT have been determined within about 10 K from the critical temperature by measurements of refractive index. The critical exponent β was deduced precisely from (T, n), (T,φ), and (T, ψ) coexistence curves within 1.5 K above Tc. These values were 0.327, 0.324, and 0.325, respectively, and were consistent with the 3D Ising exponent. The volume fraction is a better choice of the concentration variable than ψ used for construction of the order parameter to fit the Ising behavior.
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【期刊论文】Turbidity Measurements of Binary Polystyrene Solutions Near Critical Solution Points
沈伟国, Weiguo Shen, Gareth R. Smith, t Charles M. Knobler, and Robert L. Scott*
J. Phys. Chem. 1991, 95, 3376-3379,-0001,():
-1年11月30日
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沈伟国, Fei Jing a, Xueqin Ana, b, ∗, Weiguo Shen a
Journal of Molecular Catalysis B: Enzymatic 24-25(2003)53-60,-0001,():
-1年11月30日
The enzymatic activities of wheat germ lipase (WGL) (EC.3.1.1.3; triacylglycerol hydrolase) in water-in-oil (w/o) microemulsions of sodium bis-(2-ethylhexyl) sulfosuccinate (AOT)/cyclohexane/water have been investigated by using triolein as the substrate through measurements of absorbency of the product of hydrolysis at the wavelength of 707 nm in the course of reactions. Maximum enzyme activity was obtained at ω0 (molar ratio of water to surfactant)=9, pH=7.4 and T=40℃. The activation energy of the reaction was calculated from the Arrhenius plot. It was found that the hydrolysis reaction obeyed Michaelis-Menten kinetics in the investigated concentration range (0.01-0.15 mol/l) of the substrate, and the apparent Michaelis constant Km,a and the apparent maximal reaction rate Vm were determined. The stability of wheat germ lipase in w/o microemulsions was also examined and discussed.
Wheat germ lipase, Triolein, Hydrolysis, Water-in-oil microemulsion
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沈伟国, 郝小娟①, 安学勤①②, 陈志云①, 沈伟国①*
科学通报卷2003,24(48):2524~2527,-0001,():
-1年11月30日
分别测量了结晶紫(CV)在一系列水溶液中和在一系列以双一2一乙基已基硫代琥珀酸钠(AOT)为表面活性剂的油包水微乳液体系中的吸光度,用缔合模型处理实验数据,得到缔合平衡常数,发现在溶液中有高达57%的CV与AOT形成缔合物,这可能是结晶紫碱性褪色反应在含阴离子表面活性剂的微乳液体系中受禁阻的原因。
微乳液, 平衡常数, 结晶紫, AOT
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沈伟国, HAO Xiaojuan, AN Xueqin, , CHEN Zhiyun & SHEN Weiguo
Chinese Science Bulletin 2004 Vol. 49 No.4 317-320,-0001,():
-1年11月30日
The absorbance of crystal violet (CV) in a series of aqueous solutions and a series of sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/water microemulsions has been determined. Association models have been used to analyse the experimental data to obtain the association constants of CV and AOT in the above two media. It was found that about up to 57% CV was associated by AOT in OT/isooctane/water microemulsions, which reduced the reaction rate of alkaline fading of crystal violet in the microemulsions.
microemulsions,, association constant,, crystal violet,, AOT.,
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