Regulation of polyamide-66 lamellar crystal for superhydrophobicity and enhanced anti-icing performance

Abstract

The superhydrophobic surface with multilevel micro/nano structures exhibits significant potential for applications in ice prevention, sensing, self-cleaning, and surface-enhanced Raman spectroscopy. However, issues such as the poor robustness of the micro/nano structures and the intricate preparation processes remain major challenges that hinder the commercialization of superhydrophobic surfaces. In this study, we report a method for preparing superhydrophobic polyamide 66 (PA66) surface lamellar through a two-step incubation process, combined with the modification using octadecyltrichlorosilane (OTS). By adjusting the density and height of the PA66 lamellae, we not only achieve excellent superhydrophobicity on the surface of the lamellar structure (WCA = 155.7 ± 2.1°, WSA = 3.57°), but also enhance its resistance to chemical corrosion and water droplet impact. Moreover, the pattern of this film can trap air in the micro/nano structures, suppressing heat conduction, leading to an anti-icing effect. The ice-water mixing time of the droplets is significantly prolonged to 277 s, and the adhesion strength of ice decreases from 277.43 kPa (original PA66 film) to 41.62 kPa. Compared to the single-incubation PA66 lamellar film, the adhesion strength of ice after treatment is reduced by a factor of thirteen. In addition, S-PA66TIF has good ultraviolet (UV) shielding properties and shows high light stability even after continuous UV irradiation (365 nm) for more than 6 h. This study provides novel insights for designing and developing superhydrophobic surfaces and novel anti-icing materials. It also demonstrates the precision control of flexible polymer lamellar structures via a simple and versatile strategy, which can be used in more scenarios, such as the construction and fine regulation of micro/nanostructures or patterns on material surfaces.