Facile synthesis and size control of spherical aggregates composed of Cu(2)O nanoparticles

The secondary structures of Cu(2)O nanoparticles were prepared in aqueous solution utilizing self-assembled aggregation process. By introducing polyacrylamide (PAM) as a secondary surfactant, the colloidal nanoparticle aggregates (CNAs) become uniform in size and exhibit spherical shape compared to the random aggregates without PAM. The size of CNA can be systematically controlled from 300nm to 1000nm by varying PAM concentration. The formation mechanism was explained based on a conventional colloidal particle formation mechanism. These control methods may generally be applied to the preparation of secondary nanoparticle structures.