Rendering superhydrophobic laser-induced rough surfaces by transferring on them hydrophobic polymeric nanoparticles
Authors: Bayer I., Brandi F., Cingolani R., Athanassiou A.
Autors Affiliation: Center for Biomolecular Nanotechnologies at UNILE, Istituto Italiano di Tecnologia (IIT), Via Barsanti 1, 73010 Arnesano, Lecce, Italy;
Italian Institute of Technology (IIT), via Morego 30, 16152 Genova, Italy
Abstract: By using nanosecond pulsed UV laser irradiation surfaces of polished and unpolished silicon/SiO2 wafers were patterned to induced certain degree of roughness to control their wetting properties from superhydrophilic to superhydrophobic. By varying the laser fluence, it is possible to control in a systematic and reproducible way the surface roughness, and thus the wettability properties of the silicon/SiO2 surfaces. In particular, in our experiments the laser beam was focused using a cylindrical lens with focal length 75 mm, and the fluence used was between 0.5 and 2.0 J/cm2. The silicon wafers were placed in liquid, methanol or distilled water, with 5 mm of liquid covering them. The wafers were moved in precise steps using a x-y translation stage. After the laser treatment, submicron (~ 150 nm) Teflon® particles were deposited onto the rough surfaces by a dry-transfer technique to modify the surface hydrophobicity. In this way highly hydrophilic patterned surfaces could be rendered hydrophobic to superhydrophobic depending on the underlying roughness.
More Information: – Clean Technology and Sustainable Industries Organization (CTSI); European Patent Office; Greenberg Traurig; Innovation and Materials Science Institute; Jackson Walker L.L.P.KeyWords: Laser patterning; Superhydrophobic; Teflon; Micro and nanostructuring