Preparation of LaB6 nanoparticles as a novel and effective near-infrared photothermal conversion material

Abstract LaB 6 nanoparticles have been prepared successfully by a stirred bead milling process. The anionic surfactant dodecylbenzenesulfonic acid was found to be suitable for the grinding and dispersion of LaB 6 powders, but cationic surfactant polyethyleneimine and nonionic surfactant polyethylene glycol could not yield a stable dispersion. Three kinds of grinding beads with the diameters of 50, 100, and 200 μm all could reduce the mean hydrodynamic diameter of LaB 6 powders to about 100 nm. However, although the grinding rate was slower, using the smaller grinding beads with a diameter of 50 μm could yield a dispersion of LaB 6 nanoparticles with more uniform size. The resulting LaB 6 nanoparticles were confirmed to remain a cubic structure and the contaminant from ZrO 2 beads was below 5 wt%. Furthermore, the LaB 6 nanoparticles exhibited a characteristic absorption around 1000 nm and possessed an excellent near infrared (NIR) photothermal conversion property better than Au nanoshells. Because they were relatively cheap and easy-to-preparation than Au nanorods or nanoshells, the LaB 6 nanoparticles could be used as a novel and effective NIR photothermal conversion material and might find great potential in the biomedical application.