Laser fragmentation of organic microparticles into colloidal nanoparticles in a free liquid jet
Year: 2010
Type: article
Abstract: We present a novel approach for laser fragmentation of melamine cyanurate microcrystals suspended in liquid into colloidal nanoparticles. Laser fragmentation is done by irradiating a liquid jet of melamine cyanurate suspended in water with intense picosecond pulses. The free liquid jet is generated by a nozzle with small diameter and provides a thin liquid filament (d fil<1 mm) perpendicular to the focused laser beam. This geometry allows tight focusing resulting in high intensities without the danger of damaging an optical element like windows necessary in conventional flow cells or cuvettes. It reduces losses of excitation light by avoiding scattering or absorption in front of the focus. We stabilized the nanoparticles electrosterically in-situ with neutral and polyelectrolytic polymers preventing agglomeration and precipitation. The threshold for sufficient stabilization of laser-fragmented nanoparticles (d hydrodyn≈200 nm) is reached at a mass fraction of 0.25 wt% dextrin as a neutral polymer and 0.01 wt% polyacrylic acid as a polyelectrolytic polymer. Hydrodynamic size and zeta-potential of the nanoparticles can be controlled by mass fraction of the stabilization agent.
Source: Applied Physics A
Authors: Philipp Wagener, Stephan Barcikowski
Institution: Laser Zentrum Hannover
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,790
OpenAlex ID: W2025323020