Silica and montmorillonite-supported silica nanoparticles were prepared via an acid one step sol-gel process. The synthesized
solids were characterized using XRD, FTIR, TEM and N2 adsorption. The effect of preparing temperatures on
the structure and properties of the silica nanoparticles were studied. The results show that the increase of annealing
temperature from 25 to 200°C, don’t change amorphous state of silica. While for montmorillonite-supported silica the
clay platelets are delaminated during the sol-gel process. TEM results showed that the average particle size of silica is
increased by increasing temperature due to the particle sintering and the clay-silica nanoparticles possessed core–shell
morphology with diameter of 29 nm. The surface area measurements showed that by increasing annealing temperature
the surface area was decreased due to aggregation of particle. The clay-silica sample showed lower average pore width
than that of the silica prepared at 200°C indicating that it has a macropores structure. The adsorption efficiency of the
prepared samples was tested by adsorption of protoporphyrin IX. The highest adsorption efficiency was found for SiO2
prepared at 200°C. Temkin model describe the equilibrium of adsorption of protoporphyrin IX on caly-silica nanoparticles
under different conditions. |
