Distribution of coexisting solid and fluid phases alters the kinetics of collapse from phospholipid. monolayers

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

To determine how coexistence of liquid-expanded (LE) and tilted-condensed (TC) phases in phospholipid monolayers affects collapse from the air/water interface, we studied binary films containing dioleoyl phosphatidylcholine- dipalmitoyl phosphatidylcholine (DPPC) mixtures between 10 and 100% DPPC. Previously published results established that this range of compositions represents the LE-TC coexistence region at the equilibrium spreading pressure of 47 mN/m. When held at 49.5 mN/m on a captive bubble, the extent of total collapse fit with the LE area predicted by the phase diagram. The kinetics of collapse, however, when normalized for changes in the LE area, slowed with increasing mole fraction of DPPC. Surface area expressed as stretched exponential functions of time yielded an Avrami exponent that decreased from 1 for the homogeneously LE film to 0.3 for DPPC ≥ 70%. Microscopic studies showed that the largest changes in kinetics occurred when either alterations of the initial composition or the process of collapse induced the films to cross the percolation threshold, so that the LE phase became divided into isolated domains. Our results show that although coexisting solid and fluid phases collapse to extents that are independent, the kinetics of collapse, corrected for differences in LE area, depend on the distribution of the two phases.

Original languageEnglish (US)
Pages (from-to)22064-22070
Number of pages7
JournalJournal of Physical Chemistry B
Volume110
Issue number44
DOIs
StatePublished - Nov 9 2006

Fingerprint

Phospholipids
solid phases
Monolayers
1,2-Dipalmitoylphosphatidylcholine
Kinetics
Fluids
fluids
kinetics
Liquids
liquids
exponential functions
Exponential functions
Chemical analysis
liquid phases
bubbles
Phase diagrams
phase diagrams
exponents
thresholds
air

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Distribution of coexisting solid and fluid phases alters the kinetics of collapse from phospholipid. monolayers. / Yan, Wenfei; Hall, Stephen (Steve).

In: Journal of Physical Chemistry B, Vol. 110, No. 44, 09.11.2006, p. 22064-22070.

Research output: Contribution to journalArticle

@article{48f1259fc42b46f9a96617291158f53d,
title = "Distribution of coexisting solid and fluid phases alters the kinetics of collapse from phospholipid. monolayers",
abstract = "To determine how coexistence of liquid-expanded (LE) and tilted-condensed (TC) phases in phospholipid monolayers affects collapse from the air/water interface, we studied binary films containing dioleoyl phosphatidylcholine- dipalmitoyl phosphatidylcholine (DPPC) mixtures between 10 and 100{\%} DPPC. Previously published results established that this range of compositions represents the LE-TC coexistence region at the equilibrium spreading pressure of 47 mN/m. When held at 49.5 mN/m on a captive bubble, the extent of total collapse fit with the LE area predicted by the phase diagram. The kinetics of collapse, however, when normalized for changes in the LE area, slowed with increasing mole fraction of DPPC. Surface area expressed as stretched exponential functions of time yielded an Avrami exponent that decreased from 1 for the homogeneously LE film to 0.3 for DPPC ≥ 70{\%}. Microscopic studies showed that the largest changes in kinetics occurred when either alterations of the initial composition or the process of collapse induced the films to cross the percolation threshold, so that the LE phase became divided into isolated domains. Our results show that although coexisting solid and fluid phases collapse to extents that are independent, the kinetics of collapse, corrected for differences in LE area, depend on the distribution of the two phases.",
author = "Wenfei Yan and Hall, {Stephen (Steve)}",
year = "2006",
month = "11",
day = "9",
doi = "10.1021/jp056989z",
language = "English (US)",
volume = "110",
pages = "22064--22070",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "44",

}

TY - JOUR

T1 - Distribution of coexisting solid and fluid phases alters the kinetics of collapse from phospholipid. monolayers

AU - Yan, Wenfei

AU - Hall, Stephen (Steve)

PY - 2006/11/9

Y1 - 2006/11/9

N2 - To determine how coexistence of liquid-expanded (LE) and tilted-condensed (TC) phases in phospholipid monolayers affects collapse from the air/water interface, we studied binary films containing dioleoyl phosphatidylcholine- dipalmitoyl phosphatidylcholine (DPPC) mixtures between 10 and 100% DPPC. Previously published results established that this range of compositions represents the LE-TC coexistence region at the equilibrium spreading pressure of 47 mN/m. When held at 49.5 mN/m on a captive bubble, the extent of total collapse fit with the LE area predicted by the phase diagram. The kinetics of collapse, however, when normalized for changes in the LE area, slowed with increasing mole fraction of DPPC. Surface area expressed as stretched exponential functions of time yielded an Avrami exponent that decreased from 1 for the homogeneously LE film to 0.3 for DPPC ≥ 70%. Microscopic studies showed that the largest changes in kinetics occurred when either alterations of the initial composition or the process of collapse induced the films to cross the percolation threshold, so that the LE phase became divided into isolated domains. Our results show that although coexisting solid and fluid phases collapse to extents that are independent, the kinetics of collapse, corrected for differences in LE area, depend on the distribution of the two phases.

AB - To determine how coexistence of liquid-expanded (LE) and tilted-condensed (TC) phases in phospholipid monolayers affects collapse from the air/water interface, we studied binary films containing dioleoyl phosphatidylcholine- dipalmitoyl phosphatidylcholine (DPPC) mixtures between 10 and 100% DPPC. Previously published results established that this range of compositions represents the LE-TC coexistence region at the equilibrium spreading pressure of 47 mN/m. When held at 49.5 mN/m on a captive bubble, the extent of total collapse fit with the LE area predicted by the phase diagram. The kinetics of collapse, however, when normalized for changes in the LE area, slowed with increasing mole fraction of DPPC. Surface area expressed as stretched exponential functions of time yielded an Avrami exponent that decreased from 1 for the homogeneously LE film to 0.3 for DPPC ≥ 70%. Microscopic studies showed that the largest changes in kinetics occurred when either alterations of the initial composition or the process of collapse induced the films to cross the percolation threshold, so that the LE phase became divided into isolated domains. Our results show that although coexisting solid and fluid phases collapse to extents that are independent, the kinetics of collapse, corrected for differences in LE area, depend on the distribution of the two phases.

UR - http://www.scopus.com/inward/record.url?scp=33751322060&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33751322060&partnerID=8YFLogxK

U2 - 10.1021/jp056989z

DO - 10.1021/jp056989z

M3 - Article

C2 - 17078641

AN - SCOPUS:33751322060

VL - 110

SP - 22064

EP - 22070

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 44

ER -