title: Nonionic diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains: thermotropic and lyotropic liquid crystalline phase behaviour.
abstract: The thermotropic and lyotropic liquid crystalline phase behaviour of a series of diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains (geranoyl, H-farnesoyl, and phytanoyl) has been investigated. When neat, both H-farnesoyl and phytanoyl diethanolamide form a smectic liquid crystalline structure at sub-zero temperatures. In addition, all three diethanolamides exhibit a glass transition temperature at around -73 °C. Geranoyl diethanolamide forms a lamellar crystalline phase with a lattice parameter of 17.4 Å following long term storage accompanied by the loss of the glass transition. In the presence of water, H-farnesoyl and phytanoyl diethanolamide form lyotropic liquid crystalline phases, whilst geranoyl diethanolamide forms an L(2) phase. H-farnesoyl diethanolamide forms a fluid lamellar phase (L(α)) at room temperature and up to ∼ 40 °C. Phytanoyl diethanolamide displays a rich mesomorphism forming the inverse diamond (Q(II)(D)) and gyroid (Q(II)(G)) bicontinuous cubic phases in addition to an L(α) phase.
authors: CSIRO Materials Science and Engineering, PO Box 184, North Ryde, NSW, 1670, Australia.
authors: Sharon M
authors: SM
authors: Sagnella
authors: Charlotte E
authors: CE
authors: Conn
authors: Irena
authors: I
authors: Krodkiewska
authors: Calum J
authors: CJ
authors: Drummond
mesh_terms: D004983:Ethanolamines / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D050866:Liquid Crystals / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D013696:Temperature; D013729:Terpenes / Q000737:chemistry*
chemical_list: D004983:Ethanolamines; D013729:Terpenes