EVAPORATION DRIVEN SELF ASSEMBLY OF NANOPARTICLES DURING SPRAY DRYING:: VOLUME FRACTION DEPENDENT PACKING.

BAHADUR, J.; SEN, D.; MAZUMDER, S.; PAUL, BHASKAR; KHAN, ARSHAD

Hierarchically structured micrometric mesoporous silica spheres have been synthesized by evaporation driven self assembly of silica colloids under slow drying condition. The inter particle correlation inside grains has been investigated by small-angle neutron scattering. In a slow drying regime, droplets shrink isotropically leading to spherical dried grains. However, the packing of nanoparticles depends on the initial colloidal concentration. The packing of the nanoparticles for low colloidal concentration is uniform throughout the grain but at higher concentration of the colloids, dried grains possess nonuniform radial packing of the nano-particles. The average packing fraction of the nanoparticles decreases with increasing colloidal concentration due to modification in viscosity of the colloidal dispersion prior to drying.

MOLECULAR self-assembly; EVAPORATION (Chemistry); NANOPARTICLES; SPRAY drying; MESOPOROUS materials; SILICA; NEUTRON scattering; PACKING (Mechanical engineering); COLLOIDS

International Journal of Nanoscience, 2011, Vol 10, Issue 4/5, p995

0219-581X

Academic Journal

10.1142/S0219581X11008484