Photon-energy programming of layered montmorillonite: wavelength-resolved picosecond lasers for additive-free...

Functionalized montmorillonite (Mt) has been extensively studied for multi-performance optimization and additive manufacturing, but research on adjusting adsorption, thermal stability and mechanical strength without the need for additives is limited. The functionalized Mt. by 355 nm, 532 nm and 1064 nm picosecond lasers is realized and compared. A multi-scale characterization framework is established to relate energy deposition of different-wavelength lasers to microstructure, pore topology, chemical state transitions, thermal stability, and strength. The relationship between the effect of laser energy and wavelength on Mt. structure and properties is determined. Under 355 nm picosecond irradiation, Mt. exhibited a d₀₀₁ of 15.33 Å, exhibiting a higher adsorption capacity, while maintaining thermal stability and hardness. At 532 nm, at an intensity of 0.75 J/cm², the adsorption capacity increased by 102.87 %, while at an intensity of 12 J/cm², densification resulted in an 80-fold increase in hardness, indicating a viable balance between mechanical properties and adsorption. At 1064 nm, the microstructure is basically preserved; the adsorption amount increases by 16.36 % and the hardness increases by 8.9-fold. Therefore, these findings link laser energy deposition to the microstructure and applicability of Mt., revealing the mechanism of additive-free laser-programmed Mt. functionality.