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Heterogeneous freezing on pyroelectric poly(vinylidene fluoride‐co‐trifluoroethylene) thin films
Author(s) -
Apelt Sabine,
Höhne Susanne,
Uhlmann Petra,
Bergmann Ute
Publication year - 2020
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.6778
Subject(s) - materials science , pyroelectricity , supercooling , composite material , thin film , poling , crystallinity , surface roughness , annealing (glass) , surface finish , chemical engineering , surface energy , coating , ferroelectricity , nanotechnology , optoelectronics , dielectric , thermodynamics , physics , engineering
Active deicing of technical surfaces, such as for wind turbines and heat exchangers, currently requires the usage of heat or chemicals. Passive coating strategies that postpone the freezing of covering water would be beneficial in order to save costs and energy. One hypothesis is that pyroelectric active materials can achieve this because of the surface charges generated on these materials when they are subject to a temperature change. High‐quality poly(vinylidene fluoride‐co‐trifluoroethylene) (P(VDF‐TrFE)) thin films with a high crystallinity, prefererd edge‐on orientation, low surface roughness, and comprised of the β ‐analogous ferroelectric phase were deposited by spin‐coating. Freezing experiments with a cooling rate of 1 K min −1 were made on P(VDF‐TrFE) coatings in order to separate the effect of different parameters such as the poling direction, film thickness, used solvent, deposition process, underlying substrate, and annealing temperature on the achievable supercooling. The topography and the underlying substrate significantly changed the distribution of freezing temperatures of water droplets in contact with these thin films. In contrast, no significant effect of the thickness, morphology, or pyroelectric effect of the as‐prepared domain‐state on the freezing temperatures was found.