title: Determination of phase transition temperatures of lipids by light scattering.
abstract: Various techniques have been proposed to specify the phase transition temperatures of surfactant molecules. The work reported herein deals with a new general method of T(c) determination based on the optical properties' modifications of aqueous surfactant solutions when the phase transitions occur in the phospholipid membrane. The shape alteration of supramolecular systems induced by the phase transition was correlated with the refraction and absorption coefficients of their aqueous dispersion. The mean count rate (average number of photons detected per second) measured with a Zetasizer Nano-S model ZEN1600 Dynamic Light Scattering Instrument, is representative of an emerging macroscopic phenomenon, but not directly size dependent and has been adapted to our expectations. Changes in the measured scattering intensity reflect changes in the optical properties of the material during temperature variations. Thus, this method allowed to specify the phase transition temperature of many natural or synthetic surfactants independently of their polar head or hydrophobic part.
authors.affiliation: Laboratoire de Chimie Bioorganique et des Systèmes Moléculaires Vectoriels, Faculté des Sciences, 33 Rue Louis Pasteur, 84000 Avignon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Michel
authors.forename: Anne-Sylvie
authors.initials: AS
authors.lastname: Fabiano
authors.forename: Ange
authors.initials: A
authors.lastname: Polidori
authors.forename: Robert
authors.initials: R
authors.lastname: Jack
authors.forename: Bernard
authors.initials: B
authors.lastname: Pucci
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D066298:In Vitro Techniques; D008027:Light; D008055:Lipids / Q000737:chemistry*; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D010316:Particle Size; D012542:Scattering, Radiation; D013501:Surface-Active Agents / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D008055:Lipids; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D013501:Surface-Active Agents; D015060:1,2-Dipalmitoylphosphatidylcholine