| 摘要 |
Concentrated aqueous silica sols of small silica particles about 10 nm or less in diameter and uniformly sized are prepared by a process for maintaining a constant number of silica nuclei particles prior to the deposition process. The process for maintaining a constant number of silica nuclei particles in the sol consists of forming the particles at a pH 8-10.5 and a low temperature then heating the sol through a transition temperature to a deposition temperature, maintaining the pH, removing alkali metal ions and simultaneously adding alkali metal silicate from the system at a rate such that the number of silica particles in the sol remains constant while the temperature is being raised.
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