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Wetting reversal transition in phase‐separated polymer mixtures
Author(s) -
Genzer Jan,
Heier Jakob,
Kramer Edward J.
Publication year - 1999
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19991390109
Subject(s) - wetting , monolayer , polymer , layer (electronics) , phase transition , materials science , surface energy , phase (matter) , substrate (aquarium) , wetting layer , deuterium , wetting transition , analytical chemistry (journal) , chemistry , thermodynamics , composite material , chromatography , nanotechnology , organic chemistry , physics , oceanography , quantum mechanics , geology
We investigate a wetting reversal transition in thin films of two‐phase mixtures of poly(ethylene‐propylene) (PEP) and its deuterated analogue (dPEP) on a substrate covered by a self‐assembled monolayer (SAM) whose surface energy, γSAM , is tuned by varying the SAM composition. As γSAM increases from 21 to 24 mJ/m 2 , a transition from a three‐layer (air/dPEP/PEP/dPEP/SAM) to a two‐layer (air/dPEP/PEP/SAM) structure occurs at increasing T c ‐ T, where T c and T are the critical and transition temperatures, respectively. As the system structure changes from three‐layer to two‐layer, the thicknesses of the dPEP‐rich wetting layers at the air/mixture and mixture/SAM interfaces are found to smoothly increase and decrease, respectively, while the thickness of the PEP‐rich layer (ca. one half of the total film thickness) does not change. The dependence of the transition temperature on γSAM is predicted by a simple model using the experimental data on the surface energies of PEP/dPEP and estimates of the interfacial energy between PEP and dPEP.