Anti-icing properties of a superhydrophobic surface in a salt environment: an unexpected increase in freezing delay times for weak brine droplets

Phys Chem Chem Phys. 2016 Jan 28;18(4):3131-6. doi: 10.1039/c5cp06988b.

Abstract

Superhydrophobic coatings on the aluminum alloy were fabricated by intensive nanosecond pulsed laser treatment and chemical surface hydrophobization, which are chemically stable in contact with 0.5 M NaCl aqueous solutions and mechanically durable against stresses arising in the repetitive freezing/thawing of brine. The statistics of the crystallization of ensembles of sessile supercooled droplets deposited on above superhydrophobic coatings indicate considerable anti-icing properties. The comparative analysis of crystallization statistics of deionized water and of brine at a temperature of -20 °C allows detecting a striking increase in freezing delay times for the latter case with freezing delay for brine droplets reaching more than 6 hours. We explain the observed phenomenon based on the structure of the double electric layer in the vicinity of the hydrophobic surface and the solution/air interface and on the concept of structure making/breaking ions.

Publication types

  • Research Support, Non-U.S. Gov't