| Abstract
| - Two different samples of monodisperse Stöber silica particles were examined using three differentmicroscopies: energy-filtered analytical transmission electron microscopy (EFTEM), high-resolution field-emission scanning electron microscopy (FESEM), and scanning probe microscopy, in the noncontact atomicforce (AFM) and scanning electric potential microscopy (SEPM) modes. Upon drying the silica dispersions,the larger (ca. 141 nm) particles were only partially deformed by capillary adhesion, whereas the smallerparticles (ca. 36 nm) were strongly deformed and closely packed into dense films of a low porosity, whichis evidence of their larger plasticity, or superplasticity. Electric potential distribution maps obtained bySEPM showed a significant interparticle as well as intraparticle contrast, especially in the case of thesmaller particles. Examination by electron backscattering also revealed a larger contrast among the smallerparticles, thus evidencing a nonuniformity of chemical composition. The results are interpreted consideringthe changes in the synthetic medium and other aspects of the particle growth mechanism, and they pointtoward the possibility of exploiting the plasticity of the nanosized silica particles in the making of silicamonoliths.
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