Non-sticky superhydrophobicity on polypropylene surfaces achieved via single-step femtosecond laser-induced processing in n-hexadecane liquid

The preparation of superhydrophobic polypropylene (PP) surfaces for biosafety is a pressing challenge in the food and medical industries. We achieve superhydrophobicity on commercial PP using a single-step process based on femtosecond (fs) laser-induced micro/nano texturing in n-hexadecane. Analysis of the wetting behavior after fs laser texturing revealed that 120 times of repetitive texturing, with a contact angle (CA) exceeding 150° and a rolling angle below 1° yielded optimal results. The generation, growth, and evolution of micro/nanostructures over processing times were investigated to establish a direct correlation between the micro/nanostructures and hydrophobicity. Furthermore, we elucidated the interactions between fs laser pulses and different material types in air, water, and n-hexadecane to explain the formation of micro/nanostructures formed in n-hexadecane.