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Stability of Adsorbed Polystyrene Nanolayers on Silicon Substrates
Author(s) -
Jiang Naisheng,
Cheung JustinM.,
Guo Yichen,
Endoh Maya K.,
Koga Tadanori,
Yuan Guangcui,
Satija Sushil K.
Publication year - 2018
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201700326
Subject(s) - dewetting , polystyrene , materials science , spinodal , wetting , polymer , adsorption , chemical engineering , silicon , annealing (glass) , wetting layer , glass transition , layer (electronics) , polymer chemistry , solvent , chemical physics , nanotechnology , composite material , phase (matter) , chemistry , organic chemistry , engineering , metallurgy
The solid–polymer melt interface is of great scientific interest due to its vital importance in governing a wide array of physical and mechanical properties of polymer thin films. Recent studies have elucidated the coexistence of two different chain conformations of polymer chains adsorbed on a solid (i.e., loosely adsorbed chains and flattened chains). In this work, film stabilities of the polystyrene (PS) “interfacial sublayer” (composed of outer loosely adsorbed chains and inner flattened chains) and flattened layer (composed of the lone flattened chains) prepared on silicon (Si) substrates are investigated. The atomic force microscopy studies reveal that the as‐rinsed PS flattened layer is subjected to spinodal‐like dewetting during a post‐thermal annealing process even at temperatures below the bulk glass transition temperature. Furthermore, it is found that the surface morphology of the flattened layer can be reversibly changed from a homogeneous pattern under good solvent conditions to spinodal‐like droplets under poor solvent conditions. By contrast, it is found that the PS interfacial sublayer remains stable under both good and poor solvent conditions. These findings illuminate the role which density variations within the adsorbed layers play in the mechanism behind the wetting‐dewetting transition.