How to Select Phase Change Materials for Tuning Condensation and Frosting?

Abstract

Synthetic surfaces engineered to regulate phase transitions of matter and exercise control over its undesired accrual (liquid or solid) play a pivotal role in diverse industrial applications. Over the years, the design of repellant surfaces has transitioned from solely modifying the surface texture and chemistry to identifying novel material systems. In this study, selection criteria are established to identify bio-friendly phase change materials (PCMs) from an extensive library of vegetable-based/organic/essential oils that can thermally respond by harnessing the latent heat released during condensation and thereby delaying ice/frost formation in the very frigid ambient that is detrimental to its functionality. Concurrently, a comprehensive investigation is conducted to elucidate the relation between microscale heat transport phenomena during condensation and the resulting macroscopic effects (e.g., delayed droplet freezing) on various solidified PCMs as a function of their inherent thermo-mechanical properties. In addition, to freeze protection, many properties that are responsive to the thermal reflex of the surface, such as the ability to dynamically tune optical transparency, moisture harvesting, ice shedding, and quick in-field repairability, are achievable, resulting in the development of protective coatings capable of spanning a wide range of functionalities and thereby having a distinctive edge over conventional solutions.

Adhesion of impure ice on surfaces

“…We tested other materials (aluminum, stainless steel, poly-tetrafluoroethylene) also, and consistently observed adhesive failure, yielding IAS values consistent with literature reports, thereby validating the reliability of our test setup and adopted protocol. 12,13 Next, we replaced pure water with 1 wt% sodium chloride aqueous solution and froze it on the copper surface under the same conditions, and repeated the experiments to obtain IAS. Here, weight percentage refers to the mass ratio of the contaminant ( e.g.…”

“…Thus, understanding the fundamental mechanisms of ice adhesion to surfaces is crucial for developing effective de-icing technologies, improving materials with anti-icing properties, and ensuring safety in various fields, including aviation, energy production, transportation, and building design. 8,9 In this endeavor, several methods, including centrifugal and shear-removal 10–13 have been devised to measure the ice adhesion strength and then extensively used to study it on various surfaces such as common materials, non-wetting surfaces, oil-infused surfaces, gels etc. 11,14–19 A common element in all these studies is that the ice used in them was formed by freezing pure water.…”

Green synthesis of a thermo/photochromic doped cellulose polymer: a biocompatible film for potential application in cold chain visual tracking

“…Importantly, was no ice formation that obscured its visibility or affecting the composite film under sub-freezing conditions, contrasting with occurrences in other reported systems. 70 The thermal fading curves at different temperatures are reported in Figure 9b and reveal that the composite film CMC-5@15% can maintain its staining after irradiation with UV light for several weeks only if stored at temperatures below 4°C. Indeed, the film strips preserved at -19°C and 4°C have maintained a high staining (> 40%) even after 7 weeks The peak intensity at 470 nm recorded at t0 (film just irradiated) was considered as 100%, while that of the curve recorded after the complete fading of the staining (which overlaps that of the nonirradiated film) has been taken as 0%, as shown in Figure 10 Leveraging this property, we propose a labelling system incorporating photochromic film as a 'sensor' on product packaging or their containers (Figure 11).…”

Photo-thermal waxgels with fast wax layer regeneration ability for anti-icing

“…16,17 Despite the bright application prospects of waxgels, 18-21 certain challenges remain. 22,23 For example, L. Jiang et al…”

“…Despite the bright application prospects of waxgels, 18–21 certain challenges remain. 22,23 For example, L. Jiang et al reported a type of paraffin-based organogel material with a renewable sacrificial alkane surface layer, which was essentially a layer of wax that possessed excellent anti-icing properties. 24 However, the regeneration of the wax layer takes a long time at room temperature (>24 hours).…”