Synergistic effects of ionic liquid integrated superhydrophobic composite coatings on anti-icing properties

• Ionic liquid integrated PDMS/SiO 2 NPs composite fabricated by spray coating process . • DFT calculations were performed to study ion dipole interaction between PDMS and IL. • Presence of IL on surface is responsible for formation of a quasi-liquid layer (QLL). • The QLL formation was reduced the ice adhesion strength and delays in freezing. • The superhydrophobic surface significantly reduced the water-to-coating contact area. Ice accretion on surfaces presents significant challenges across various applications. To address this, hydrophobic polymer/ionic liquid (IL) composite coatings have emerged as effective solutions for enhancing anti-icing properties. In this study, we explored the potential of a poly(dimethylsiloxane) (PDMS)/IL/SiO 2 nanoparticle (NP) composite, employing two synergistic strategies: superhydrophobicity to reduce the ice/coating contact area and IL-induced quasi-liquid layer (QLL) formation to improve anti-icing performance. Density functional theory (DFT) calculations and structural analyses were performed to confirm IL dispersion within PDMS matrix, highlighting ion–dipole interactions between PDMS and 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide (EMIMTFSI). IL-integrated PDMS/SiO 2 composite exhibited a water contact angle (WCA) and water sliding angle (WSA) of 166.6 ± 0.5° and 4 ± 1°, respectively. The PDMS/IL/SiO 2 NPs composite coating exhibited an ice adhesion strength (IAS) of 19 ± 1 kPa, which is four times lower than that of the PDMS/SiO 2 NPs composite. Additionally, the IL-integrated superhydrophobic composite exhibited the FDT of 325 ± 6 s, representing a 14-fold increase compared to that of a bare Al substrate. Overall, the IL-integrated coatings exhibited superior superhydrophobicity and QLL formation, leading to significantly improved FDT and a notable reduction in IAS. These sprayable IL-based composites show great promise as practical anti-icing coatings for extreme cold environments.