Wettability of microstructured Pyrex glass with hydrophobic and hydrophilic properties

- New grooved hybrid surfaces with hydrophobicity and hydrophilicity was fabricated on a Pyrex glass.
- The laser-induced backside wet etching (LIBWE) process was used for machining a glass surface.
- Hybrid surfaces influence the wettability and condensation of water.
- Water filled the hydrophilic surface of the groove, not the hydrophobic surface of the ridge.

A grooved hybrid surface that has silane-coated surface (hydrophobic surface) on ridges and uncoated surface (hydrophilic surface) inside groove was fabricated on a Pyrex glass substrate through the laser-induced backside wet etching (LIBWE) process. The wettability characteristics of the grooved hybrid surface were evaluated from static contact angles (CAs) measured in parallel and orthogonal directions. With an increase in the width of the hydrophobic ridge, the CAs increased from 24° to 104° in the parallel direction. Consequently, the anisotropic wetting property of the fabricated hybrid surface was confirmed. Results of moisture condensation experiments indicated that moisture condensed rapidly in the hydrophilic grooves. Furthermore, the diffuse reflection of light was prevented when the groove was completely filled with water.

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