The effects of the number of fatty acid residues (n) in decaglycerol fatty acid esters, i.e., decaglycerol laurates (abbreviated to (C-11)(n)G(10)), on the phase behaviors of three laurate esters, (C-11)(1.9)G(10),(C-11)(2.7)G(10), and (C-11)(3.4)G(10), were investigated. The unreacted decaglycerol remaining in each ester was removed by liquid extraction before use. (C-11)(1.9)G(10) formed hexagonal liquid crystals in aqueous solutions, while (C-11)(2.7)G(10) and (C-11)(3.4)G(10), which are more hydrophobic than (C-11)(1.9)G(10), formed lamellar liquid crystals. The cloud point in aqueous solution was measured for mixtures of these three esters. The cloud phenomenon was observed when the weight ratio of hydrophilic groups to the total surfactant (WH/WS) was around 0.6. The cloud point shifted to a markedly higher temperature, even with a slight increase in the WH/WS ratio. The solubilization abilities of (C-11)(n)G(10) fortheoils ni-xylene and (R)-(+)-limonene were also examined. When the W-H/W-S ratio was between 0.60 and 0.64, (C-11)(n) G(10) formed microemulsions and lyotropic liquid crystals in the presence of water and the oils. These self-organized structures were stable, even above 90 degrees C. It is Concluded that the phase behavior of (C-11)nG(10) are insensitive to temperature, but strongly dependent on both the W-H/ W-S ratio and the number of fatty acid residues (n). (c) 2005 Elsevier Inc. All rights reserved.