Confinement and compression of an oligomer brush.
Self-assembled monolayers and oligomer brushes confined between two parallel plates show compressional forces that are nonmonotonic as a function of plate separation. In a realistic model of short alkanethiols, based on the rotationally isomeric state model with parameters from ab initio calculations, the authors show that nonmonotonic forces arise from the elimination of longer conformers as the distance between the plates is reduced. This nonmonotonicity is a size effect that disappears when the length of the polymer molecule is sufficiently increased. An analytical model is developed that allows experimentalists to extract energy-averaged brush height distributions from compressional force curves.
Foster
Stephen
S
Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 3J5, Canada.
Wainwright
Christopher
C
Staple
Douglas B
DB
Kreuzer
Hans Jürgen
HJ
D003651:Decanoates / Q000737:chemistry*; D008954:Models, Biological; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
D003651:Decanoates; D011108:Polymers; D013438:Sulfhydryl Compounds