Evaluation of Anti-Icing/De-Icing Performance of PU Topcoat with CNT Addition in Aircraft Applications

Icing on aircraft can lead to increased weight, reduced lift, and pose a risk of accidents. Methods for removing aircraft icing include the use of deicing solutions like glycol or employing techniques such as heating and vibration. However, these methods have limitations in terms of applicable areas, energy consumption, duration constraints, and low efficiency. To prevent ice formation on the aircraft itself, anti-icing methods are employed.<br/> Anti-icing methods involve surface etching on metal surfaces or the application of hydrophobic polymer coatings. Commonly used polymers for this purpose are polytetrafluoroethylene (PTFE) and polyurethane due to their ability to cure at room temperature and compatibility with base materials like epoxy. To enhance hydrophobic effects, research is exploring the addition of hydrophobic nanoparticles to create nanostructured surfaces. Nanoparticles, acting as binders, form the topcoat in the coating layer. However, nano surfaces face challenges related to durability and sustainability.<br/> In this study, a nanostructured surface was achieved by incorporating hydrophobic nanoparticles, specifically carbon nanotubes (CNT), into the polymeric topcoat. Polyurethane was utilized as the topcoat, and CNT dispersed in a solvent such as xylene was sprayed after coating. To address durability issues associated with previously researched nano surfaces, CNT was dispersed in the binder to enhance the strength of the topcoat and increase the adhesion between the binder and the exposed CNT on the surface. Additionally, the conductivity of CNT dispersed in the topcoat contributed to higher thermal conductivity compared to coating CNT only on the surface.<br/> To expose hydrophobic CNT on the surface, some hardening of the topcoat surface was induced before coating with xylene. This allowed for the manifestation of the hydrophobic effect from the carbon surface of CNT and also contributed to surface morphology effects induced by CNT. The addition of CNT increased the contact angle with water from 74.3 degrees to 121.2 degrees, resulting in a significant delay in icing effects, approximately a 260% increase. Moreover, a decrease in adhesion time and strength of ice on the surface was observed. When a current of 3V was applied, a temperature increase of about 54 degrees was noted, effectively causing the ice to melt and slide off.<br/> Ongoing research involves investigating the impact of surface roughness changes on aircraft wings or similar structures when applied as an actual model. The study aims to understand the influence of surface variations on aircraft wings and related components.<br/>This work was partly supported by Korea carbon Industry Promotion Agency grant funded by the Ministry of Trade, Industry and Energy (RS-2023-0026563). This research was supported by the National Research Foundation of Korea(NRF) funded by the Ministry of Science and ICT (RS-2023-00211944). This work was supported by Policy R&D program funded by Korea Ceramic Engineering & Technology, Republic of Korea(No. KPP23006-0-01).