Spectroscopic Studies of Polymerized Surfactants: 1,2-bis(10,12-tricosadiynoyl)-sn-Glycero-3-Phosphocholine.

摘要

Spectroscopic studies have been performed on aqueous dispersions of the surfactant-1,2-bis(10,12-tricosadiynoyl-sn-glycero-3-phosphocholine before and af polymerization with ultraviolet light. Monomers of this lipid can, under certain conditions, convert from the expected spherical liposomal form to a unique phase consisting of hollow tubules. To determine the molecular conformation of these structures we have used Raman and infrared spectroscopies to probe the structure of the hydrocarbon chains and head groups of the lipids, and used absorption spectroscopy and resonance-enhanced Raman scattering of the colored polymer to monitor the length and structure of the diacetylenic polymer backbone. Unusual C-H stretching Raman bands imply that the hydrocarbon chain packing in the monomeric bilayers is different from that observed in other phosphatidylcholines, and that a disturbance in alkyl chain packing occurs on polymerization. Depending on irradiation conditions and the dispersal state of the lipid the polymer chains may be of at least three different colors, from which distinct resonance Raman spectra are obtained. (js)