부산대학교 도서관

In this letter, we describe a method to control the organization and thickness of multilayered phospholipid films. The meniscus of an organic solution of phospholipid molecules was dragged at a speed von a solid substrate under controlled temperature and forced convection, leading to the deposition of a dried multilayered phospholipid film with a thickness hin the range of 20−200 nm. We found two distinct regimes dominating the film deposition. At low speeds, phospholipid molecules accumulate near the contact line and form a dry film behind the meniscus (evaporation regime). At high speed, viscous forces become predominant and pull out a liquid film that will dry afterward (Landau−Levich regime). Both regimes show robust scaling h∝ vαwith α = −1.1 and 0.76, respectively. Although these regimes have been observed separately in the past, they have not been demonstrated in the same material system. Moreover, we present models whose scalings (α = −1 and 2/3) are in close agreement with the observed values. The microscale organization of the resulting film is independent of vfor a given regime but differs from one regime to another. In the Landau−Levich regime, his very homogeneous on the microscale with discrete variations of ±5 nm, that is, the thickness of one bilayer. [ABSTRACT FROM AUTHOR]