Enhancing Hydrophobicity of Polymer Thin Film-Coated Surface by Wrinkling Method

• Published in: Macromolecular research Vol. 28; no. 12; pp. 1104 - 1110
• Main Authors: Byeon, Minseon, Cho, Seong Keun, Um, Min Seop, Lee, Jae Heung, Kim, Eun Seon, Choi, Woo Jin
• Format: Journal Article
• Language: English
• Published: Seoul The Polymer Society of Korea 01.11.2020; 한국고분자학회
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex Fluids and Microfluidics; Nanochemistry; Nanotechnology; Physical Chemistry; Polymer Sciences; Soft and Granular Matter; 고분자공학; surface wrinkling and buckling; hydrophobic surface; surface morphology
• ISSN: 1598-5032; 2092-7673
• DOI: 10.1007/s13233-020-8158-1

The hydrophobicity of film surfaces can be enhanced by introducing wrinkling and buckling, and the wrinkling method in this study is a facile way to induce various microstructures including wrinkles and buckles in film surfaces. When buckles formed, the water contact angle parallel to the wrinkled direction ( θ // ) changed dramatically with strain, but the contact angle perpendicular to the wrinkled direction did not change much. It was found that the buckle structural feature was the key characteristics affecting the change in contact angle, θ // . A dimensionless number, the ratio of buckle height to spacing ( H b / S b ) was introduced to determine the relationship between the structural feature and the contact angle, θ // . The contact angle, θ // strongly depended on H b / S b . The thickest film ( h f = 605 nm) at the highest strain (ɛ = 30%) and the highest H b / S b formed many large buckles, and exhibited super-hydrophobicity ( θ // = 169 ± 10°).