Morphological development of multilamellar phospholipid film depending on drying kinetics

The mechanism for the formation of solid-supported phospholipid membranes during a drying process was investigated. Terracelike multilamellar structures were found to develop from a micellar solution with either spinodal decompositionlike process or nucleation growth, depending on the evaporation rate of an organic solvent. In contrast to the well-known kinetics of phase separation, fast drying induces nucleation while slow drying induces spinodal decompositionlike lipid-film formation. The existing models for the interpretation of phase separation are not sufficient to understand this unexpected kinetics. We suggest a schematic model with which this kinetic feature can be interpreted in terms of a self-assembly pathway in a three-component phase diagram for a phospholipid, organic solvent, and water.