Status and demand of research to bring laser generation of nanoparticles in liquids to maturity

Nanoparticles are already implemented as functional elements on surfaces and into volume, but also in hybrid nanostructures. Each application requires specific features regarding size, morphology, surface chemistry, purity, colloidal stability, defects, or doping. However, integration of the nano-function into products is still limited due to drawbacks of gas phase and chemical synthesis methods regarding particle aggregation and contamination by adsorbates causing deactivation of their surfaces. In addition, thermodynamically-controlled synthesis methods naturally face limited access to alloy nanoparticle systems with miscibility gaps. The development of new synthesis methods which can be reliably scaled up to industrial levels of production is mandatory to overcome these limitations and then widen the application prospectives of nanomaterials. Since the nineties, Laser Ablation in Liquids (LAL) has proven its reliability and its versatility to synthesize colloidal nanoparticles. More generally, laser/matter interaction in liquids offers several synthesis routes for nanoparticle generation. In addition to LAL, Laser Melting in Liquids (LML), Laser Fragmentation in Liquids (LFL), as well as pulsed Laser Photoreduction/oxidation in Liquids (LPL), offer different routes to obtain colloids with controled nanoparticle sizes. We will present a digest of the breakthroughs achieved in the last years not only on the synthesis control, but also on the understanding of the basics. These achievements suggest that laser generation of nanoparticles in liquids is mature enough for industrial outlets of colloid production, with series products likely to approach the real world in the near future.