Thermodynamic behavior and relaxation processes of mixed DPPC/cholesterol monolayers at the air/water interface

Tzung Han Chou, Chien Hsiang Chang

Research output: Contribution to journalArticlepeer-review

67 Citations (Scopus)

Abstract

This study investigated the thermodynamic behavior and relaxation processes of mixed DPPC/cholesterol monolayers at the air/water interface at 37°C. Surface pressure-area isotherms and relaxation curves for the mixed monolayers were obtained by using a computer-controlled film balance. In the thermodynamic analysis of the mixed monolayers, the areas of monolayers exhibited negative deviations from the ideal values at all compositions for lower surface pressures. However, at higher surface pressures, distinctively positive deviations from ideality were observed at lower DPPC contents. Excess free energies of mixing had been calculated and the most stable state of the mixed monolayer with x(DPPC) = 0.5 or 0.6 was found. Moreover, the relaxation kinetics of the mixed monolayers was investigated by measuring the surface area as a function of time at a constant surface pressure of 40 mN m-1. It was shown that the relaxation processes could be described by the models considering nucleation and growth mechanisms.

Original languageEnglish
Pages (from-to)71-79
Number of pages9
JournalColloids and Surfaces B: Biointerfaces
Volume17
Issue number2
DOIs
Publication statusPublished - 2000 Feb 15

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Surfaces and Interfaces
  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Thermodynamic behavior and relaxation processes of mixed DPPC/cholesterol monolayers at the air/water interface'. Together they form a unique fingerprint.

Cite this