|464. Reinhardt, M.; Dzubiella, J.; Trapp, M.; Gutfreund, Ph.; Kreuzer, M.; Gröschel, A.H.; Müller, A.H.E.; Ballauff, M.; Seitz, R.: Fine-Tuning the Structure of Stimuli-Responsive Polymer Films by Hydrostatic Pressure and Temperature, Macromolecules 46, 6541-6547 (2013) -- DOI: 10.1021/ma400962p|
The response of stimuli-responsive polymer brushes to moderately elevated pressure is investigated by neutron reflectivity and a thermodynamically consistent density functional theory where pressure effects are included by a hydrophobic cavity model. Evidence is provided that temperature and pressure effects on the brush spatial structure are entirely antagonistic. A ~100 bar/K cancellation effect is found, which we argue is a general feature for hydrophobically associating homopolymers and serves for experimental guidance and fine-control of polymer film structure. Our results also suggest that polymeric interfaces which do not show a marked temperature dependence are also rather insensitive to pressure effects for applied pressures below 1 kbar.