Characterization of nanoscale titanium nitride dispersions by small-angle neutron scattering

Suspensions of nanoscale titanium nitride (TiN) with a high solids content can be prepared by using guanidino propionic acid (GPA) as a stabilizing agent. The steric effect of an organic shell with polar groups on the surface of TiN spheres has been suggested in the literature as being a reason for the colloidal stability. To verify this hypothesis experimentally, we have performed small-angle neutron scattering (SANS) on this system; there is no evidence of an organic shell. Even at higher concentrations, in accordance with the Percus-Yevick theory, we could not observe any significant interparticular ordering. A plausible explanation for the stabilization of TiN suspensions is the buffer action of the amino acid GPA.