Study On Fabrication Of Superhydrophobic Solar Glass Surface Morphology By Picosecond Laser And Its Wettabicity

Glass is a commonly used material that can be used in automotive windshields,house construction,solar cell enclosures and electronic displays.In addition to anti-fog,anti-corrosion,anti-icing,anti-snow,water repellent and self-cleaning properties,the surface of superhydrophobic glass has two advantages: dust does not easily adhere and maintain high transparency on rainy days.Generally speaking,there are two ways for the preparation of superhydrophobic material:(1)to construct a rough structure on the hydrophobic material,and(2)to reduce the surface energy of the rough structure.The traditional methods of fabricating micro/nano-structures on the glass surface include mechanical etching,lithography,coating technology,plasma etching.However,these methods are still limited by complicated preparation process,expensive instrument,and vacuum environment.In comparison,laser fabrication technique has many advantages such as non-contact,short action time and ultrahigh peak power.This paper researched the effects of picosecond laser parameters(pulse energy and laser line interval)on the surface micromorphology and hydrophobicity of solar glass through picosecond laser irradiation.In addition,the transmittance of superhydrophobic solar glass in the visible spectrum was measured and analyzed.The main research results are as the following:(1)The superhydrophobic solar glass surface was successfully prepared by the combination of picosecond laser etching and fluorosilane modification.By optimizing the laser process parameters,the solar glass surface is etched under the laser process parameters of laser pulse energy of 40 ?J,frequency of 400 kHz,scans number of 50 and the laser line interval of 60 ?m.A periodic microgroove arrays with many nano-protrusions were prepared on the solar glass surface.The contact angle of fluorosilane-modified solar glass surface is 169°±1° and the rolling angle is less than(2)By adjusting the process parameters of the picosecond laser,the effects of different laser process parameters on the surface morphology and wettability of soalr glass were studied.When the laser line interval is 60 ?m,the frequency is 400 kHz and the number of scans is 50,laser pulse energy increasing from 32 ?J to 42 ?J.The spacing between the surface microgrooves is approximately 60 ?m and the aspect ratio of the microgroove increases.The contact angles of fluorosilane-modified solar glass surface increase by 157°±2° to 170°±1° and rolling angles are less than 2°.When the laser pulse energy is 35 ?J,the frequency is 400 kHz and the number of scans is 50,the laser line interval increases from 50 ?m to 85 ?m.The spacing between microgrooves of the surface increases and the contact angles of fluorosilane-modified glass surface decrease from 172°±1° to 145°±3°.At laser line interval of 85 ?m,the rolling angle increases obviously.(3)The hydrophobic mechanism of solar glass surface was analyzed by establishing hydrophobic structure model and calculation.The results show that the nano-protrusions inside the micro-grooves and the nano-holes on the surface are conducive to increase the hydrophobicity of the solar glass surface,and can limit the water droplet transition from the Cassie state to the Wenzel state on the solar glass surface.These nanostructures play a crucial role in the formation of superhydrophobic glass surface and the very low contact angle hysteresis of the surface.