Jia Yu

Bio: Jia Yu is an academic researcher from Aston University. The author has contributed to research in topics: Epoxy & Sandpaper. The author has an hindex of 1, co-authored 1 publications receiving 1 citations.

Novel superhydrophobic carbon fiber/epoxy composites with anti-icing properties

Abstract: In this study, novel carbon fiber/epoxy (CF/EP) composites with anti-icing properties were made using a combination of octadecylamine modification and hard templating. First, the octadecylamine-modified epoxy resin was sprayed on the surface of CF/EP prepreg. Hierarchical micro/nanostructures were formed on the surfaces of the composites through hot pressing with aluminum templates that had been modified by sandblasting and anodizing. The resulting composites were superhydrophobic, with static contact angles of up to 155° and sliding angles as low as 8°. Superhydrophobicity was maintained after abrading with 400 grit SiC sandpaper. The anti-icing properties of the composites were quantified by measuring droplet freezing time and ice adhesion force. Compared to untreated CF/EP, the surface treatments used here increased the time to freeze a 5 μL surface droplet from 76 to 640 s at − 20 °C, and reduced ice adhesion strength from roughly 74 kPa to 50 kPa.

Designing Durable Icephobic Surfaces

Abstract: Researchers successfully design materials with extremely low ice adhesion. Ice accretion has a negative impact on critical infrastructure, as well as a range of commercial and residential activities. Icephobic surfaces are defined by an ice adhesion strength τice < 100 kPa. However, the passive removal of ice requires much lower values of τice, such as on airplane wings or power lines (τice < 20 kPa). Such low τice values are scarcely reported, and robust coatings that maintain these low values have not been reported previously. We show that, irrespective of material chemistry, by tailoring the cross-link density of different elastomeric coatings and by enabling interfacial slippage, it is possible to systematically design coatings with extremely low ice adhesion (τice < 0.2 kPa). These newfound mechanisms allow for the rational design of icephobic coatings with virtually any desired ice adhesion strength. By using these mechanisms, we fabricate extremely durable coatings that maintain τice < 10 kPa after severe mechanical abrasion, acid/base exposure, 100 icing/deicing cycles, thermal cycling, accelerated corrosion, and exposure to Michigan wintery conditions over several months.

Superhydrophobic Epoxy/Fluorosilicone/PTFE Coatings Prepared by One-Step Spraying for Enhanced Anti-Icing Performance

Abstract: The icing of glass insulators is likely to cause faults such as insulator flashover, which poses a serious threat to the power system. Traditional deicing techniques have the disadvantage of being costly and inefficient. Herein, polytetrafluoroethylenes (PTFEs) as nanoparticles and epoxy and fluorosilicone resins as binders were blended to construct an anti-icing coating. The superhydrophobic (SHP) epoxy/fluorosilicone/PTFE coatings for anti-icing were successfully prepared on glass slides through one-step spraying. The effect of PTFE mass fraction on the microstructure, on the wettability and on the anti-icing properties of the coatings was investigated. The results showed that the coatings with different PTFE mass fractions had different microstructures. When the PTFE mass fraction was 47.2%, the SHP coating exhibited a uniform rough structure with an apparent contact angle as high as 164.7° and a sliding angle as low as 3.2°. Moreover, the water droplets can bounce back five times with a contact time of only 9.5 ms and a rebound height of 4.58 mm. In the low-temperature environment (−10 °C), the SHP coating displayed good anti-frosting, anti-icing and icephobic properties. The delayed frosting time (1499 s) and delayed freezing time (1295.3 s) of the SHP coating were three and five times longer than those of the glass, respectively. The SHP coating presented an ice-adhesion strength (39.8 kPa) that was six times lower than that of glass. The prepared SHP coating demonstrated potential applications for the anti-icing of glass insulators.

Role of Molecular Chains Arrangement and Surface Energy State in the Low Ice Adhesion on Poly(tetrafluoroethylene).

Abstract: The relation between polymer molecular chains arrangement and ice adhesion was studied at the molecular scale, and the energy states of water molecules on the poly(tetrafluoroethylene) surface were analyzed to explain the energy essence of ice adhesion. The ice adhesion on crystalline poly(tetrafluoroethylene) displayed a clear anisotropy phenomenon. Further research proved that the energy states of water molecules along the vertical direction of the molecular chains fluctuated regularly, and the water molecules in gaps between molecular chains were in the energy troughs, leading to the formation of energy traps. Water molecules needed more energy from outside to escape the energy traps, causing additional resistance to the ice movement and obvious increase of ice adhesion. Therefore, ice adhesion was closely related to the distribution of energy traps in the direction of ice removing, which mainly depended on the possibility of molecular chains perpendicularly arranged in the direction of ice removing.