Dispersed Lipid Liquid Crystalline Phases Stabilized by a Hydrophobically Modified Cellulose

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• 作者：Mats Almgren ; Johanna Borné ; Eloi Feitosa ; Ali Khan ; Bjö ; rn Lindman
• 刊名：Langmuir
• 出版年：2007
• 出版时间：February 27, 2007
• 年：2007
• 卷：23
• 期：5
• 页码：2768 - 2777
• 全文大小：1462K
• 年卷期：v.23,no.5(February 27, 2007)
• ISSN：1520-5827

文摘

Aqueous dispersions of monoolein (MO) with a commercial hydrophobically modified ethyl hydroxyethyl celluloseether (HMEHEC) have been investigated with respect to the morphologies of the liquid crystalline nanoparticles. Onlyvery low proportions of HMEHEC are accepted in the cubic and lamellar phases of the monoolein-water system.Due to the broad variation of composition and size of the commercial polymer, no other single-phase regions werefound in the quasi-ternary system. Interactions of MO with different fractions of the HMEHEC sample induced theformation of lamellar and reversed hexagonal phases, identified from SAXD, polarization microscopy, and cryogenicTEM examinations. In excess water (more than 90 wt %) coarse dispersions are formed more or less spontaneously,containing particles of cubic phase from a size visible by the naked eye to small particles observed by cryoTEM. Athigh polymer/MO ratios, vesicles were frequently observed, often oligo-lamellar with inter-lamellar connections. Afterhomogenization of the coarse dispersions in a microfluidizer, the large particles disappeared, apparently replaced bysmaller cubic particles, often with vesicular attachments on the surfaces, and by vesicles or vesicular particles witha disordered interior. At the largest polymer contents no proper cubic particles were found directly after homogenizationbut mainly single-walled defected vesicles with a peculiar edgy appearance. During storage for 2 weeks, the dispersedparticles changed toward more well-shaped cubic particles, even in dispersions with the highest polymer contents.In some of the samples with low polymer/MO ratio, dispersed particles of the reversed hexagonal type were found.A few of the homogenized samples were freeze-dried and rehydrated. Particles of essentially the same types, but witha less well-developed cubic character, were found after this treatment.