532 nm picosecond laser processing of montmorillonite: Multi-scale insights into framework reconstruction and property optimization

Abstract

Global pursuit of environmentally sustainable materials has increased interest in layered silicates like montmorillonite. Few studies address additive-free, pollution-free methods to enhance its properties. We examined 532 nm picosecond laser irradiation on montmorillonite at 0.75–12 J/cm2. Theoretically, a two-temperature model combined with molecular dynamics predicts rapid energy deposition, lattice instability, and structural transformations. Experimentally, x-ray diffraction characterization showed peak shifts, indicating interlayer compaction and lattice collapse. Macroscopic analysis combined with physical and chemical principles related to molecular dynamics shows enhanced adsorptive property and thermal stability at intermediate energy densities. At high energy, Vickers hardness rose from 7.36 to 647.77 Hv. Picosecond laser irradiation, thus, drives non-equilibrium dynamics in montmorillonite, enabling precise control over structural and functional properties. These findings expand its potential in eco-friendly remediation, thermally stable adsorbents, and high-strength industrial components.