Thermal behavior of 1,2-dipalmitoyl-sn-3-phosphoglycerocholine bi- and multi-layers, deposited with physical vapor deposition under ellipsometric growth control

J Chem Phys. 2012 Apr 7;136(13):134709. doi: 10.1063/1.3698486.

Abstract

1,2-dipalmitoyl-sn-3-phosphoglycerocholine membranes were deposited onto a silicon substrate (Si/SiO(2)) using physical vapor deposition with in situ ellipsometric thickness control. Along several heating cycles it was possible to identify well-defined boundaries for gel, ripple, liquid crystalline, and fluid-disordered phases. Particularly, the second order transition between gel and ripple phase was clearly identified in the range of ~28-34 °C using Raman spectroscopy. Atomic force microscopy and imaging ellipsometry (IE) were used to observe and characterize the ripple phase undulations of period λ = 20.8 nm and average height h = 19.95 nm along the temperature interval of ~34 to 40 °C. Clusters/agglomerations heights of more than twice the membrane thickness were observed with IE, induced by heating cycles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1,2-Dipalmitoylphosphatidylcholine / chemistry*
  • Buffers
  • Lipid Bilayers / chemistry*
  • Temperature*
  • Volatilization

Substances

  • Buffers
  • Lipid Bilayers
  • 1,2-Dipalmitoylphosphatidylcholine