Tailoring surface interactions, contact angles, drop topologies and self-assembly using laser irradiation

TL;DR

This study demonstrates how UV laser irradiation can precisely modify borosilicate surfaces to control water contact angles and influence nanoparticle self-assembly, enabling tailored surface properties and improved material fabrication.

Contribution

It introduces a laser-based method to tune surface wettability and shape, enhancing nanoparticle self-assembly and surface patterning capabilities.

Findings

Laser processing achieves over 25° variation in contact angle.

Asymmetric contact angles lead to ellipsoidal drop shapes.

Improved self-assembly of silica microwires observed.

Abstract

UV laser irradiation (lambda = 193 nm), below and above damage thresholds, is used to both alter and pattern the surface properties of borosilicate slides to tune and control the contact angle of a water drop over the surface. Large variation exceeding 25 deg using laser processing alone, spanning across both sides of the original contact angle of the surface, is reported. An asymmetric contact angle distribution, giving rise to an analogous ellipsoidal-like drop caplet, is shown to improve convective self-assembly of silica nanoparticles into straighter microwires over a spherical caplet.