The band centered at 469 cm−1 is due to the bending frequency of Si-O-Si. A large broad band around 3,429 cm−1 is attributed to the presence of the O-H stretching frequency for the silanol group and the remaining adsorbed water. A band around 1,630 cm−1 is assigned to the bending vibration of water molecules bound to the silica matrix. No peak was found between 2,800 and 3,000 cm−1. It means that there were no original organic compounds in the silica after controlled combustion and extraction. This result corresponds well with the carbon measurement by CHN analysis reported in Table 4. The FTIR spectra showed no significant changes in the peak position for extracted silica and nanosilica.