Nanoparticle formation in a cavitation bubble after pulsed laser ablation in liquid studied with high time resolution small angle x-ray scattering

We investigated nanoparticle formation after pulsed laser ablation in liquid using time-resolved small angle x-ray scattering. Laser ablation of a gold target in water induces a cavitation bubble in which two different particle species could be identified at maximum bubble extension: (i) primary particles of about 8-10 nm diameter, which show a smooth concentration gradient starting from the target and can also be found outside the cavitation bubble in the free liquid and (ii) secondary particles in the range of 45 nm diameter which have highest concentration in the upper part of the cavitation bubble but do not penetrate into the liquid. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4750250]