The effect of octyl glucoside on rheological behavior of diluted and concentrated lamellar phases

Lyotropic liquid crystalline phases formed in ternary mixtures of 1-cetyl-3-methylimidazolium bromide/p-xylene/water: A SAXS, POM, and rheology study

“…According to the SAXS results, the higher surfactant content leads to denser aggregation of the surfactant molecules in the hexagonal liquid crystalline phase, which further induces exchange of the surfactant molecules between the cylinder unit and the aqueous phase, so that the values of τ of the hexagonal phase decline as the surfactant content increases. For the lamellar phase, the storage modulus is slightly higher than the loss modulus over the whole frequency range, indicating that the phases correspond to a "weak gel" [43]. Meanwhile, the dynamic moduli are practically independent of the frequency, and these properties are in agreement with those of lamellar liquid crystalline phase formed from traditional surfactants [44].…”

An HII liquid crystal-based delivery system for cyclosporin A: Physical characterization

“…Polar lipids and certain surfactants can form lyotropic liquid crystals (LLC) [1][2][3][4][5][6][7][8][9]. Among the mesophases formed by glycerol mono fatty acids (monoglycerides) and water are lamellar (L α ), reverse hexagonal (H II ), and cubic liquid crystalline structures (Q G or Q D ).…”

Lamellar Liquid Crystals Formed in Ternary DEP/Oil/Water Systems

“…Their nomenclature and composition are given in Table 1. reported [17] that the shear rate dependence on the viscosity for the lamellar phases could be described by a power law of the following form g ¼ g 1 c n . However, usually the flow curve does not fit the power law in the whole shear rate region.…”

“…The found exponents were between À0.38 and À0.45 for lamellar liquid crystals formed in TRITON N-101=water system depending on surfactant concentration. [17] The authors pointed to the lamellar phases showing structural defects related to very highly curved regions in the bilayers. Granizo and coworkers [19] also supposed that the lamellar phase formed in C 12 E 4 þ OG=hexanol=water system, having a exponent of À0.37, composed of crystallites with random alignment rather than indefinite long sheets of structured of materials.…”

“…This tendency may reflect the relatively high density of structural defects appearing in the microstructure of lamellar phase at higher water content [20,21] and the production of metastable defects can lead to an increase in viscosity. [17] Generally, the bilayered lamellar structures of surfactants exhibit shear-thinning behavior with a yield stress. [22] The yield stress is the minimum stress required to enable flow or fracture of a materials due to the breakdown or alteration of the microstructure.…”