Does the snow queen like black? Nanocarbon and biosilica-reinforced THV-based anti-icing sponges

Abstract

New superhydrophobic, anti-icing tetrafluorethylene-hexafluorpropylene-vinylidenfluoride terpolymer (THV)-based materials: nonporous solids as well as porous sponges were created and deeply characterized using thermal analysis, spectroscopy, resistivity measurements, cyclic compression tests, and confocal microscopy. Single walled carbon nanohorns (SWCNHs), biosilica (BS) as well as carbonized biosilica (CB) were applied as fillers. The “combined” origin of superhydrophobicity is explained based on experimental water contact angles (WCA) and molecular dynamics (MD) as well as Hansen Solubility Parameters (HSP) analysis. For all materials thermal resistance is improved after the addition of fillers, but among the studied samples only for the sample containing SWCNHs the application of electrothermal/Joule heating to reinforce anti-icing properties is possible. We propose a new forcefield for MD simulation of THV wetting. Moreover, MD results revealed that water freezing at the “flat” THV surface was moderately inhibited with respect to the bulk freezing and considerably inhibited with respect to the graphene surface. Introduction of SWCNHs to THV causes not only remarkable improvement of mechanical properties but also the improvement of anti-icing properties, especially to the stage of recalescence. The comparison of results for porous and nonporous materials led to new correlations describing freezing on the cold plate process, being a starting point for future studies on a new model describing the freezing mechanism. The most important conclusion of the complex study (around 100 samples altogether) is that the creation of mechanically resistant THV-SWCNHs-containing sponges is the most promising strategy in modern anti-icing science leading not only to enhancement of the compression Young's modulus and the time to recalescence, but also to the drop of freezing temperature.