Preparation of Ion-exchanged Zeolite Nanoparticles by Laser Irradiation in Liquid and their Properties

Zeolite nanoparticles were prepared by laser irradiation of zeolites or ion-exchanged zeolites. Using ion-exchanged zeolite as a raw material, metal cations introduced into the pores caused local laser absorption, and zeolite nanoparticles were produced with a minimum size of 50 nm. X-ray diffraction and transmission electron microscopy images confirmed the crystal structure of the zeolite nanoparticles. It was found that the crystal structure was maintained up to the nanoparticles' surface. By changing the centrifugation intensity, nanoparticles of any size could be selectively recovered from dispersions containing nanoparticles with a wide size distribution. The volume zone of the obtained nanoparticles was estimated by comparing it with the calculated particle size value that all particles settled using Stokes' law.