Continuous multigram nanoparticle synthesis by high-power, high-repetition-rate ultrafast laser ablation in liquids

Abstract

Utilizing a novel laser system consisting of a 500 W, 10 MHz, 3 ps laser source which is fully synchronized with a polygon scanner reaching scanning speeds up to 500 m/s, we explore the possibilities to increase the productivity of nanoparticle synthesis by laser ablation in liquids. By exploiting the high scanning speed, laser-induced cavitation bubbles are spatially bypassed at high repetition rates and continuous multigram ablation rates up to 4 g/h are demonstrated for platinum, gold, silver, aluminum, copper, and titanium. Furthermore, the applicable, ablation-effective repetition rate is increased by two orders of magnitude. The ultrafast ablation mechanisms are investigated for different laser fluences, repetition rates, interpulse distances, and ablation times, while the resulting trends are successfully described by validating a model developed for ultrafast laser ablation in air to hold in liquids as well.

Water-based, surfactant-free cytocompatible nanoparticle-microgel-composite biomaterials – rational design by laser synthesis, processing into fiber pads and impact on cell proliferation

“…Processing this master batch blended with Polycaprolactone results in about 96 g of electrospun fiber pads, covering roughly 13.5 m 2 . The productivity could be further enhanced using an innovative high power laser system with an advanced polygon scanner system and a flow-through setup achieving nanoparticle productivities up to 4 g/h [56], which could boost the daily production of these polymer composite materials into the kilogram regime. Aiming at a bioactive release system the successful encapsulation of zinc and iron ion sources (the nanoparticles) into the polymer was confirmed by transmission electron microscopy, total organic carbon and thermal gravimetric analysis.…”

Process Chain for the Fabrication of Nanoparticle Polymer Composites by Laser Ablation Synthesis

“…For example, size quenching by micromolar anions of salts or pulsed laser fragmentation can be used to control particle sizes [41,42]. However, there is still no industrial application of these laser-generated nanoparticles due to its low productivity preventing larger-scale applications [21]. According to the technology readiness level scale (TRL), a technology assessment model used by the NASA since the 1980s and adopted by several other state agencies [43], the method is within the technology development of TRL 5 out of 9.…”

“…Nevertheless, the productivity, in general, was still very low, ranging within 5-20 mg h -1 for an actual one-hour long ablation [47]. Recent advances in ultrafast laser technology and optics, namely a new ultrafast high-power laser source and the invention of polygon scanners with high lateral scanning speed, allowed continuous nanoparticle productivities on the gram scale [21,48].…”

“…This method is attracting attention since it enables the scalable synthesis of a wide variety of different and pure colloidal nanoparticles. PLAL allows for facile synthesis of metals [21,22], metal oxides [23,24], and semiconductor nanoparticles [25,26] but it also enables an unparalleled synthesis of mixed metal (e.g., Ni-Fe) series for high-throughput screening and systematic variation of molar ratios [27] as well as metal cation-doped luminescent nanoparticles with tunable dopant concentrations [28]. Nanointegration of these laser-generated nanoparticles into polymer matrices is a promising approach to bridge the previously mentioned gap.…”

Colloidal Stability of Metal Nanoparticles in Engine Oil under Thermal and Mechanical Load

“…Depending on nanoparticle material and liquid, these laser-generated nanoparticles are highly dispersed and stable. This relatively new technique allows a simple and rapid synthesis of surfactant-free ceramic or metal nanoparticles in various liquids with high nanoparticle productivities [25][26][27][28]. A bulk material, which is immersed in a liquid, absorbs the pulsed laser beam and is evaporated until it condenses as nanoparticles in the surrounding, stabilizing medium [21,29].…”