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Liquid propylene-glycol (PG) has long been used as an anti-icing substance, for example, by spraying on an airplane parked in an airport. In applications, large quantities of PG flow away, which is costly and raises environmental concerns. Here we report propylene-glycol materials, including PG-gels and PG-gel/cotton composites. A PG-gel consists of PG molecules as a solvent and a polymer network. PG evaporates slowly, and the polymer network retains the PG molecules so long as the gel is not in contact with running water. Water and PG form a eutectic system with an eutectic temperature of −60 ◦C. When ice falls on the surface of the gel, the ice and the PG molecules compete for water molecules, and thermodynamics dictates that the ice should lose water molecules to the PG molecules, so that ice melts and water molecules dissolve in the gel. A liquid-like layer exists on the ice/gel interface, the adhesion energy between the gel and ice is low, and ice readily slides on the gel. We peel a PG-gel from ice, and measure a low adhesion energy of ∼3 Jm−2 at temperatures about −35 ◦C. We further demonstrate PG-gel/cotton composites as tough, anti-icing blankets. The blankets are reusable if one removes water by dehydration, and replenish PG by submerging the blanket in liquid PG.
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A Family of Frost‐Resistant and Icephobic Coatings
Abstract Anti‐icing and icephobic materials play a crucial role in demanding applications ranging from energy to transportation systems operating in frigid climates. Despite remarkable advancements in the development of such surface coatings, the use of anti/de‐icing chemicals remains one of the go‐to solutions for ice management. However, they are notoriously prone to removal by shear forces and dissolution. Herein, the design rationale for developing a family of cryoprotectant and phase‐change material (PCM)‐based compositions in the form of mixtures, non‐aqueous emulsions‐creams, and gels that can substantially overcome such challenges is reported. This is achieved through the sustenance of an in‐situ‐generated surface hydration layer that protects the underlying substrate from a variety of foulants, varying from ice to disease‐causing bacteria. Each formulation utilizes unique chemistry to curtail the embodied cryoprotectant loss and can be easily applied as an all‐in‐one sprayable/paintable coating capable of significantly outperforming untreated industrial materials in terms of their ability to delay condensation‐frosting and shed ice simultaneously. Concomitantly, an array of formulation‐specific functionalities is observed in the family, which includes optical transparency, mechanical durability, high shear‐flow stability, and self‐healing characteristics.
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- PAR ID:
- 10367145
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 34
- Issue:
- 20
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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