Corrosion and Biofouling Behaviors of Self-Organized Structures on Steel Surface Fabricated by Femtosecond Laser

Self-organized ripple and pillar structures are fabricated on steel surface using femtosecond laser. Their wettability is investigated in terms of static contact angle, roughness, and chemical bonds. The pillar structure is treated in low surface energy solution to further improve its hydrophobicity. The corrosion and biofouling behaviors of the structures in sea water are investigated by electrochemical and chlorella immersion experiments, respectively. The results show that the ripple structure is hydrophilic with a static contact angle similar to the original surface, while the pillar structure is highly hydrophobic since it has higher roughness and amount of non polar chemical bonds. The pillar structure is further transferred to superhydrophobic through the low surface energy treatment. The improved hydrophobicity facilitates a better anti-corrosion and anti-biofouling behavior, and the superhydrophobic pillar structure exhibits the best performance due to its strongest ability to repel water and chlorella adhesion.