Naslov
Bioinspired supramolecular membranes formation by interactions of facial bioamphiphilic anion with conventional amphiphilic cations, metal cations, or chelating ligand

Autori
Mihelj, Tea ; Tomašić, Vlasta

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
24. hrvatski skup kemičara i kemijskih inženjera

Mjesto i datum
Zagreb, Hrvatska, 21.04.2015. - 24.04.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
atipical bilayer; liquid crystal; sodium cholate; supramolecular membrane

Sažetak
Molecular self-assembly is a process in which molecules spontaneously organize into ordered assemblies by noncovalent intermolecular forces. Inspired by biological systems, the design of supramolecular membranes, liquid crystals and solid-state structures, which could be applied in biomaterials design and preparation, is studied on the basis of large cholate steroidal anion (Ch-), characterized by facial amphiphilicity, and unconventional self-aggregation (micellization) properties. Three types of complexes: catanionic, metaloamphiphilic, and host–guest complex are synthesized, and their tendency to form supramolecular membranes are examined. Various experimental techniques are used: CHN analysis, NMR, IR spectroscopy, DSC, X-ray diffraction (WAXD and SAXD), microscopy (OM and SEM), and DFT calculations. Solid catanionic amphiphiles are sythesized by the interaction of sodium cholate (NaCh) and different quaternary ammonium salts, by varying the number of n-dodecyl chains on the ionic group (nc), and the number of ionic groups (nh) in molecule. The room temperature (RT) structure of catanionics is atipical bilayer, and smectic at higher temperatures. The dependence of polymorphic and mesomorphic properties, thermodynamic parameters and bilayer thickness on nc and nh is studied. The investigation of the assembling modes of oppositely charged surfactants in catanionic forms is of great interest because different geometry, architecture and other related single surfactant abilities provide the possibility to design various resultant supramolecular structures of amphotropic properties. Metaloamphiphiles are sythesized by the interaction of NaCh with Ag(I), Ca(II), Ba(II) or La(III) salts, and also by neutralization of Ag(I) oxide or Ca(II) hydroxyde with cholic acid. Interaction of Ch– and metal cations at higher concentrations results with gelation, and bidentante coordination of Ch–. Addition of NaCh into the 18C6 ether cavity forms host–guest complex. The RT phase of addition complex is bilayered, while mesophase formed at higher temperatures is cholesteric.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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