Characterization of microemulsions formed in a water/ABA block copolymer [poly(hydroxystearic acid)-poly(ethylene oxide)-poly(hydroxystearic acid)]/1,2-hexanediol/isopropyl myristate system

Plaza, M; Tadros, TF; Solans, C; Pons, R

HERO ID

4684049

Reference Type

Journal Article

Year

2002

HERO ID 4684049
In Press No
Year 2002
Title Characterization of microemulsions formed in a water/ABA block copolymer [poly(hydroxystearic acid)-poly(ethylene oxide)-poly(hydroxystearic acid)]/1,2-hexanediol/isopropyl myristate system
Authors Plaza, M; Tadros, TF; Solans, C; Pons, R
Journal Langmuir
Volume 18
Issue 15
Page Numbers 5673-5680
Abstract Microemulsions formed with water, isopropyl myristate, PHS-PEO-PHS polymeric surfactant, and alkanediol have been investigated using small-angle X-ray scattering (SAXS) and conductivity at 25 degreesC. Isopropyl myristate has a low solubility in water; however, this molecule has some polar character because of its ester group. The conductivities of samples with some added NaCl (used here to increase the conductivity sensitivity) are low, but compared to the conductivity of water/alkanediol mixtures, the values are high for most of the samples. The X-ray scattering curves show a correlation peak if the water content is high enough. A two-phase model for the invariant calculation fits the experimental results reasonably well provided that the partition of the oil between the polar and nonpolar phases is taken into account. This partition can be obtained from the ternary water/isopropyl myristate/alkanediol system, which has some mutual-solubility regions. A hard-sphere model can be fitted to the SAXS scattering data. The volume fractions fitted from this model deviate from the volume fractions of the low-polarity phase, indicating that the structure of most of the samples is of the bicontinuous type.
Doi 10.1021/la011597e
Wosid WOS:000176903500009
Is Certified Translation No
Dupe Override No
Is Public Yes