Water induced microstructure transformation of diglycerol monolaurate reverse micelles in ethylbenzene.
نویسندگان
چکیده
Water induced microstructure transitions of diglycerol monolaurate (C(12)G(2)) reverse micelles in aromatic liquid ethylbenzene have been investigated using small-angle X-ray scattering (SAXS) and rheometry. The SAXS data have been evaluated by generalized indirect Fourier transformation (GIFT) and geometrical model fittings. We found that the C(12)G(2) spontaneously self-assembles into ellipsoidal prolate micelles in ethylbenzene under ambient conditions. The maximum diameter of the micellar core is ca. 5.0 nm. We noted that 5% C(12)G(2)/ethylbenzene solubilize 0.8% water and the water causes micellar growth; micellar size is ~ 3 times bigger than the empty micelles. Rheology data showed that viscosity of 5% C(12)G(2)/ethylbenzene increases with increase in the water concentration sustaining the SAXS results that the viscosity increase is caused due to micellar growth. We found that increase in temperature of the water incorporated system decreases micellar size, which is equivalent to a rod-to-sphere type transition. The water induced microstructure transformations can be explained in terms of critical packing parameter, cpp. Water hydrates hydrophilic headgroup of surfactant so that effective cross-sectional area of surfactant increases. As a result the cpp decreases and micelles grow. On the other hand, increasing temperature promotes interpenetration of solvent and surfactant chain as a result cpp increases due to decrease in the effective cross-sectional area of surfactant. Moreover dehydration may occur and micelles with more curved interface are formed due to increases in the cpp.
منابع مشابه
Structural investigation of diglycerol monolaurate reverse micelles in nonpolar oils cyclohexane and octane.
Structure of diglycerol monolaurate (abbreviated as C(12)G(2)) micelles in nonpolar oils cyclohexane and n-octane as a function of compositions, temperatures, and surfactant chain length has been investigated by small-angle X-ray scattering (SAXS). The SAXS data were evaluated by the generalized indirect Fourier transformation (GIFT) method and real-space structural information of particles was...
متن کاملStructure of Nonionic Surfactant Diglycerol Monomyristate Micelles in Cyclohexane: a SAXS Study
Structure of nonionic surfactant diglycerol monomyristate (C14G2) micelles in cyclohexane has been investigated by small-angle X-ray scattering (SAXS) technique. Structural modulation of reverse micelle (RM) has been systematically studied by changing composition, temperature change and added-water. The SAXS data were evaluated by the generalized indirect Fourier transformation (GIFT) method, w...
متن کاملStructure-Activity Relationship of a U-Type Antimicrobial Microemulsion System
The structure-activity relationship of a U-type antimicrobial microemulsion system containing glycerol monolaurate and ethanol at a 1∶1 mass ratio as oil phase and Tween 20 as surfactant were investigated along a water dilution line at a ratio of 80∶20 mass% surfactant/oil phase, based on a pseudo-ternary phase diagram. The differential scanning calorimetry results showed that in the region of ...
متن کاملStructure of AOT reverse micelles under shear.
Reverse micelles in the AOT/water/isooctane system, at various water contents (W(0)), were studied using rheometry and small angle X-ray scattering (SAXS) experiments under static conditions and under shear. The SAXS analysis confirmed the spherical shape of the micelles at low water content and revealed a transition into elongated micelles at higher water content. A population of spherical mic...
متن کاملStructure modifications of AOT reverse micelles due to protein incorporation.
Structural modifications of AOT/water/isooctane reverse micelles due to incorporation of proteins were studied at various water contents and protein concentrations, using small-angle X-ray scattering (SAXS) experiments under static conditions, rheometry analysis, and SR-SAXS experiments under induced shear flow. Two proteins, lysozyme (pI 11.1, Mw 14,300 Da) and BSA (pI 4.3, Mw 66,700 Da), were...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of oleo science
دوره 61 10 شماره
صفحات -
تاریخ انتشار 2012