TY - JOUR
T1 - Water solubilization in nonionic microemulsions stabilized by grafted siliconic emulsifiers
AU - Garti, N.
AU - Aserin, A.
AU - Wachtel, E.
AU - Gans, O.
AU - Shaul, Y.
PY - 2001/1/15
Y1 - 2001/1/15
N2 - Microemulsions containing octanol, decanol, or dodecanol as the oil phase and oligomeric, grafted nonionic amphiphiles based on ethoxylated polymethylsiloxanes (Silwets) have been studied. It was demonstrated that significant amounts of water can be solubilized only when the hydrophobic siliconic backbone is very short (trimers). The water solubilization was evaluated using SAXS, DSC, and conductivity measurements. It was found that up to 40 wt% of water can be solubilized in dodecanol and Silwet L-7607 (MW 1000 and 75 wt% ethylene oxide (EO)). Surprisingly, no free water was detected in the aggregate core. All the solubilized water was confined in the vicinity of the interphasal region and froze at -10°C and below. Up to three molecules of water can be associated with each EO headgroup. Based on SAXS measurements, the structural units of the microemulsions were interpreted to be lamellar-like, a form previously found for the related monomeric microemulsions.
AB - Microemulsions containing octanol, decanol, or dodecanol as the oil phase and oligomeric, grafted nonionic amphiphiles based on ethoxylated polymethylsiloxanes (Silwets) have been studied. It was demonstrated that significant amounts of water can be solubilized only when the hydrophobic siliconic backbone is very short (trimers). The water solubilization was evaluated using SAXS, DSC, and conductivity measurements. It was found that up to 40 wt% of water can be solubilized in dodecanol and Silwet L-7607 (MW 1000 and 75 wt% ethylene oxide (EO)). Surprisingly, no free water was detected in the aggregate core. All the solubilized water was confined in the vicinity of the interphasal region and froze at -10°C and below. Up to three molecules of water can be associated with each EO headgroup. Based on SAXS measurements, the structural units of the microemulsions were interpreted to be lamellar-like, a form previously found for the related monomeric microemulsions.
KW - DSC of microemulsions
KW - Microemulsions
KW - Oligomeric amphiphiles
KW - Polymeric emulsifiers
KW - Polymethylsiloxane
KW - SAXS
UR - http://www.scopus.com/inward/record.url?scp=0035862067&partnerID=8YFLogxK
U2 - 10.1006/jcis.2000.7226
DO - 10.1006/jcis.2000.7226
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AN - SCOPUS:0035862067
SN - 0021-9797
VL - 233
SP - 286
EP - 294
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
IS - 2
ER -