Dynamic Anti-Icing Coatings: Complex, Amphiphilic Hyperbranched Fluoropolymer Poly(ethylene glycol) Cross-Linked Networks with an Integrated Liquid Crystalline Comonomer

Abstract

Amphiphilic hyperbranched fluoropolymer coatings incorporating liquid crystalline moieties and poly­(ethylene glycol) cross-linkers were found to demonstrate noteworthy anti-icing properties. A series of amphiphilic networks was synthesized through variation of the polymer molecular weights and hydrophilic/hydrophobic component ratios. These innovative materials show a remarkable reduction in the free water melting transition (T m) temperature (−10 °C), measured by differential scanning calorimetry, and an increase in water contact angle for dry and water-swollen systems. The addition of this ordered parameter generated a unique coating topography, which can be visualized via polarized optical microscopy and 3D optical microscopy, while maintaining an overall macroscopic homogeneity.

Fabrication of a Highly Stable Superhydrophobic Surface with Dual-Scale Structure and Its Antifrosting Properties

“…Fog, frost, and ice formation and accumulation on the facility surfaces are known to cause serious economic and safety problems, such as ceasing the operation, impairing the efficiency, and even paralyzing the entire system, which would cause irreversible catastrophic results, especially regarding application in aircrafts, warcrafts, power lines, transportation, telecommunications equipment, dams, and heat exchangers. − For example, air-source heat pumps are generally placed outdoors to heat inner spaces and water; these pumps would lose efficiency significantly in cold climates, because of the insulating effect of frost or ice layers, and consequently increase the pressure drop in channels. − Even worse, once the condensate droplets freeze to form a frost/ice layer, rain droplets would freeze immediately when they impinge upon the cold surface, which may exacerbate the icing progress . Therefore, numerous efforts have been made in recent decades to search for freeze-delay or antifrost/anti-icing, antiwater condensation materials, which can effectively prevent ice/frost/fog formation. − Relevant results have proved that the superhydrophobic materials are promising candidates. − By now, massive superhydrophobic surfaces have been fabricated on different substrates, based on the combination of surface with micronano structures and chemical compositions of low surface energy using diverse synthetic methods. , However, such techniques are still at their infant stage and suffer many shortcomings. , Wang et al presented a flexible superhydrophobic surface with a hierarchical structure via the combination of soft-lithography and hydrothermal methods. Although the surface displayed robust anti-icing performance, the fabrication process is so complicated and harsh (the heat treatment temperature is 350 °C) that large-scale production cannot be realized .…”

Hyperbranched Macromolecules: From Synthesis to Applications

“…HMs are mostly amorphous materials, though some exceptional examples have been reported. For example, HMs have been modified to induce liquid crystallinity [ 32 , 33 ] or crystallinity [ 34 ]. The lower glass transition temperature (T g ) of HMs than of linear polymers is another important feature.…”

Synthesis of Novel Hyperbranched Polybenzo-Bisthiazole Amide with Donor–Acceptor (D-A) Architecture, High Fluorescent Quantum Yield and Large Stokes Shift

“…Over the past few decades, hyperbranched polymers have drawn continuous and considerable attention because of their unique molecular architecture, improved physical and chemical properties, and their broad range of applications, such as fluorescent probes [ 1 , 2 , 3 , 4 , 5 ], polymer coatings [ 6 , 7 ], Separation materials [ 8 ], drug or biomolecule carrier materials [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ], and in optoelectronic materials and devices [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Compared to linear polymers, hyperbranched polymers have the obvious advantages of high solubility, little chain entanglement, low viscosity, good processability, tunable light emission, low crystallinity, and controllable thin film morphology [ 27 , 28 ].…”