Abstract: Amino acid bifunctionalized mesoporous silica nanoparticles with controllable particle size and dispersibility were synthesized via the cooperative self-assembly of surfactants, co-structure-directing agents (CSDAs), and a silica source. Uniform distributions of acid and base organic groups on the mesopore surfaces were formed by interactions between the counter charged surfactant head groups and ionic parts of CSDAs. The particle size has been well tuned with different amount of co-solvent or dispersant, while the dispersibility of the bifunctionalized mesoporous nanoparticles have been achieved through changing the pH of the solution to convert the chargement between cationic ammonio-anionic carboxylate and to shift the electrostatic force between the nanoparticles.

Key words: Amino acid, Mesoporous, Nanoparticle, Dispersibility, CSDA