Self‐Cleaning Dual‐Scale Heterostructured Polyethylene Terephthalate (PET) Sheet With Anti‐Icing and UV Resistant Functionalities

Abstract Polyethylene terephthalate (PET) is widely used packaging materials for electrical encapsulation, photovoltaic components, solar junction boxes, food storage, automotive parts, etc. Endowing the PET exterior surfaces with self‐cleaning functionality offers a promising solution to improving durability by resisting dust and dirt accumulation, thereby reducing maintenance costs. A facile and effective strategy is presented for creating robust micro/nano hierarchical structures on PET sheets to achieve superhydrophobicity through surface roughening and reduced surface energy. By integrating a thermal engraving method (utilizing copper micro‐patterned templates fabricated via high‐resolution laser cutting) with polymer modification through reversible addition‐fragmentation chain transfer (RAFT) polymerization to introduce fluorinated functional groups, dual‐scale patterned PET surfaces is successfully generated. Two distinct hierarchical structures, micro‐windowpanes and microgrooves with secondary nanofeatures generated by poly (glycidyl methacrylate)‐block‐poly (pentafluorostyrene) coating, exhibited exceptional water repellent properties, with water contact angles of 155 ± 3° and 151 ± 1°, respectively. The dual‐scale micro‐windowpanes‐structured surfaces exhibited a low sliding (roll‐off) angle of 7.9°, ensuring efficient self‐cleaning performance. The newly developed multifunctional PET surfaces demonstrated outstanding water repellency and effective removal of both water‐soluble (e.g., coffee powder) and water‐insoluble (e.g., sand) contaminants, strong anti‐icing and UV resistance, highlighting their potential for low‐maintenance packaging materials and high‐performance coatings.