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4 CONCLUSION
A series of samples were synthesized by the TEOS hydrolysis method, showing that all sam-
ples were single phases and particle sizes were approximately 200 nm. The surface morphol-
ogy was spherical. Factors affecting the particle size of the sample included the magnetic
stirring rate and the pH of the reaction solution. However, the large-sized samples have
a reunion phenomenon, which was due to the fact that the reactant concentration of the
system was too high and the samples were not treated by ultrasonic dispersion after being
generated. We confirmed the inhibitory effect of nano silica on the proliferation of Hela cells
was weak through the in vitro experiment. The Hela cells were cultured for 48 h with nano
silica at the ...