Speaker
Description
Due to their size ranging from one nanometre to a few hundred nanometres, nanoparticles exhibit a high surface-to-volume ratio and specific light-matter interactions (plasmon effect) that benefit applications such as catalysis, optics, and medicine. Chemical synthesis methods dominate the market due to their strong reproducibility and tunable properties. However, these methods are highly material specific, requiring a dedicated protocol to be developed for each new composition. Moreover, the reagents involved – surfactants, reducing agents, and precursors – can persist as contaminants in the final product, raising concerns for sensitive applications. Therefore, offering a versatile, well controlled, and clean method for nanoparticle production would be a significant asset to the industry.
Pulsed laser ablation in liquid addresses some of these requirements. Briefly, a laser pulse is fired onto an immersed target, resulting in confined plasma generation and subsequent nanoparticle nucleation and growth. The method is highly versatile – it can, in principle, be applied to any bulk target – and clean, as only the target and solvent are required. However, nanoparticle growth follows diverse out-of-equilibrium mechanisms, which gives rise to several challenges. Notably, productivity remains limited, and more importantly, fine control of nanoparticle morphology is still restricted to broad size distributions and spherical particles.
To benefit from PLAL’s intrinsic cleanliness while tackling these limitations, the RAYLEIHLAB project investigates temporal and spatial beam shaping strategies. Productivity is addressed through fluence optimisation via a multiple-beam approach, while size control is pursued through finer laser-matter interaction tuning using double-pulse or donut-shaped beam configurations.