Open AccessPolymers at Liquid/Vapor Interface
Author(s) -
Brandon L. Peters,
Darin Q. Pike,
Michael Rubinstein,
Gary S. Grest
Publication year - 2017
Publication title -
acs macro letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.966
H-Index - 92
ISSN - 2161-1653
DOI - 10.1021/acsmacrolett.7b00466
Subject(s) - polymer , materials science , perpendicular , solvent , gaussian , chemical physics , power law , molecular dynamics , exponential function , side chain , thermodynamics , composite material , chemistry , organic chemistry , computational chemistry , physics , mathematical analysis , geometry , mathematics , statistics
Polymers confined to the liquid/vapor interface are studied using molecular dynamics simulations. We show that for polymers which are weakly immiscible with the solvent, the density profile perpendicular to the liquid/vapor interface is strongly asymmetric. On the vapor side of the interface, the density distribution falls off as a Gaussian with a decay length on the order of the bead diameter, whereas on the liquid side, the density profile decays as a simple exponential. This result differs from that of a polymer absorbed from a good solvent with the density profile decaying as a power law. As the surface coverage increases, the average end-to-end distance and chain mobility systematically decreases toward that of the homopolymer melt.