Same solution synthesis and self-assembly of porous silica nanoparticles into microspheres

The ability to couple self-assembly to the synthesis of materials in situ is an attractive concept for both basic and applied research. Self-assembly has been demonstrated for dense solid building blocks; however, it remains underdeveloped for porous materials, especially in situ assembly. Herein, we report the one-step synthesis and self-assembly of porous silica nanoparticles into silica microspheres by using polyvinylpyrrolidone-pentanol emulsion droplet system. Nanoparticle size can be tuned by modifying the reaction conditions.