Nanodiamond Reinforced Poly(dimethylsiloxane)-Based Polyurea with Self-Healing Ability for Fouling Release Coating

Silicone-based fouling-release coatings (FRCs) have received increasing interest because they are environmentally friendly. However, the coatings with poor mechanical properties and low adhesion to substrate are difficult to repair after damage, which limits their applications. In this study, poly(dimethylsiloxane)-based polyurea (PDMS-PUa) was modified by adding nanodiamond with perfluoroalkyl attached on the surface. The modified PDMS-PUa coating has high water contact angle (124°) and low surface energy (18 mJ m–2) due to the presence of the self-enriched perfluoro groups and polysiloxane on the surface. The introduction of fluorinated nanodiaomd improves the tensile strength of PDMS-PUa from 1.2 to 1.6 MPa and the adhesion strength from 1.5 to 2.1 MPa. Particularly, the modified PDMS-PUa exhibits self-healing performance at room temperature because of the hydrogen bonding between urea groups. Marine field tests show that the coating can keep fouling-release ability after immersion in natural seawater for four months.