A simple method for preparation of silica aerogels doped with monodispersed nanoparticles in homogeneous concentration

Silica aerogel is a solid matrix, capable of preserving the unique properties of nanoparticles incorporated in it; forming a macroscopic structure that benefits from nano-metric properties. We developed a simple method for preparation of doped silica aerogels. Dopants are implemented as silica coated nanoparticles suspended in alcohol or alcohol:water mixture. This suspension replaces a portion of the pure solvent in the one-step base catalyzed silica aerogel recipe. Aerogels doped with, Au nano-spheres, Ag nano-platelets, and CdSe/CdS core/shell quantum dots, were prepared. These aerogels exhibit homogeneous mono-dispersion of the nanoparticles, and possess the nanoparticles' unique optical properties. Additionally, doping does not affect the gelation process or the silica matrix. We envision that using this methodology, many other silica coated nanoparticles can be implemented as dopants. Furthermore, complex systems of several co-dopants can be obtained in a reproducible manner. Such aerogels can be tailor made for a vast range of applications.