Sub-zero temperature behaviour of non-ionic microemulsions in the presence of propylene glycol by DSC
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Sub-zero temperature behaviour of non-ionic microemulsions in the presence of propylene glycol by DSC. / Yaghmur, A.; Aserin, A.; Tiunova, I.; Garti, N.
In: Journal of thermal analysis and calorimetry, Vol. 69, No. 1, 26.08.2002, p. 163-177.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Sub-zero temperature behaviour of non-ionic microemulsions in the presence of propylene glycol by DSC
AU - Yaghmur, A.
AU - Aserin, A.
AU - Tiunova, I.
AU - Garti, N.
PY - 2002/8/26
Y1 - 2002/8/26
N2 - The five-component system is quite unique since it allows formation of reverse micelles with hydrophilic ethoxylated alcohol in the presence of ethanol and it facilitates dilution by water/propylene glycol (1,2-propanediol, PG) aqueous phase, all the way from a water-in-oil (W/O) microemulsion via a bicontinuous phase to an oil-in-water (O/W) microemulsion. The surfactant/alcohol/PG can strongly bound water in the inner phase so that it freezes below -10°C and acts in part as 'bound' water and in part as 'non-freezable' water. Upon dilution to >30 mass% aqueous phase (water/PG at constant mass ratio of 1/1) the system becomes bicontinuous and the aqueous layers are composed again from bound water. Even after complete inversion to O/W microemulsions the water in the continuous phase is strongly interacting with the PG/surfactant and remains bound or non-freezable. Water/PG/ethanol have a strong effect on the head groups (freezing below -10°C) and also on the hydrophobic tails (recrystallizing and melting) at lower temperature when dilution exceeds 45 mass% water/PG (1/1). No free water was detected neither in the W/O microemulsion's inner droplet domains nor when the microemulsion was either bicontinuous or when it was inversed to O/W. Continuous phase of resulting O/W microemulsion apparently is based on water/PG at a mass ratio of 1/1.
AB - The five-component system is quite unique since it allows formation of reverse micelles with hydrophilic ethoxylated alcohol in the presence of ethanol and it facilitates dilution by water/propylene glycol (1,2-propanediol, PG) aqueous phase, all the way from a water-in-oil (W/O) microemulsion via a bicontinuous phase to an oil-in-water (O/W) microemulsion. The surfactant/alcohol/PG can strongly bound water in the inner phase so that it freezes below -10°C and acts in part as 'bound' water and in part as 'non-freezable' water. Upon dilution to >30 mass% aqueous phase (water/PG at constant mass ratio of 1/1) the system becomes bicontinuous and the aqueous layers are composed again from bound water. Even after complete inversion to O/W microemulsions the water in the continuous phase is strongly interacting with the PG/surfactant and remains bound or non-freezable. Water/PG/ethanol have a strong effect on the head groups (freezing below -10°C) and also on the hydrophobic tails (recrystallizing and melting) at lower temperature when dilution exceeds 45 mass% water/PG (1/1). No free water was detected neither in the W/O microemulsion's inner droplet domains nor when the microemulsion was either bicontinuous or when it was inversed to O/W. Continuous phase of resulting O/W microemulsion apparently is based on water/PG at a mass ratio of 1/1.
KW - Differential scanning calorimetry
KW - Interphasal water
KW - Non-freezable water
KW - Non-ionic microemulsions
KW - Propylene glycol
UR - http://www.scopus.com/inward/record.url?scp=0036345463&partnerID=8YFLogxK
U2 - 10.1023/A:1019997909346
DO - 10.1023/A:1019997909346
M3 - Journal article
AN - SCOPUS:0036345463
VL - 69
SP - 163
EP - 177
JO - Journal of thermal analysis and calorimetry
JF - Journal of thermal analysis and calorimetry
SN - 1418-2874
IS - 1
ER -
ID: 221829767