Enhanced Anti-Adhesion Performance of Hydrophilic Silica-Doped Laser-Induced Graphene

Laser-induced graphene (LIG) has been widely used in various applications, including water treatment, and its surface properties, including wetting and micro/nano structure, are factors that influence its antifouling properties. Superhydrophilic surfaces minimize interactions with hydrophobic pollutants, and changing fabrication parameters can modify the wetting properties of LIG. Fabrication of nanoparticle-LIG composites increases the functionality of the material and enhances catalytic or antibacterial activities of related surfaces; however, less is known for nanoparticle-LIG composites that modulate fouling. Here, we show SiO₂-doped LIG by lasing polyethersulfone-diatomaceous earth membrane composites, which resulted in superhydrophilic surfaces with enhanced anti-adhesion and anti-bio-adhesion performance. The diatomaceous earth converted to crystalline SiO₂ that is uniformly coated on the LIG surface during the laser treatment. Increased surface oxygen-containing functional groups are also observed, which enhanced the hydrophilicity of the LIG composite. Anti-adhesion properties of the hydrophilic SiO₂-LIG are exemplified by a reduced binding of methylene blue and Pseudomonas aeruginosa, representing an organic pollutant and bacterial adhesion, respectively. The variable surface properties of silica nanocomposite surfaces might be useful in water treatment membranes, but silica-doped LIG might also lead to uses in other applications, such as sensing or semiconductors, if the electronic properties of the material can be altered.