Laser ablation of materials for nanoparticle generation is becoming increasingly important. Main advantages of the laser-based method are free of choice of the manufactured material and the purity of the non-chemical process. In case of ceramic colloids the influences of laser parameters and additives on the productivity and the stabilization of nanoparticles is not well known for the laser-based method. We investigate this aspect during laser ablation of corundum in the liquid phase using two industrial ns-pulsed lasers emitting a laser beam in the IR-wavelength.
Adjusting a liquid layer of 1 mm we reached a productivity of 2.46 g/h using pulse energy of 11 mJ at 3 kHz laser repetition rate. The particle size and the full width half maximum of the particle size distribution can be reduced by particle fragmentation of already ablated particles during the process interval of 60 min and when high laser fluences of 202 J/cm² (EP = 4 mJ) were used. We analyzed monomodal particle size distribution (particle size 80 nm; FWHM 120 nm). We observed stabilization of spherical corundum nanoparticles dispersed in a buffered aqueous solution of pH 4 to 5, adjusted by aqueous nitric acid, resulted in electrostatic stabilization of synthesized ceramic particles. Under these conditions, we determined zeta potential between -20 mV and -40 mV, where the zeta potential is directly related to the long-term stability of particles in the suspension.