Formation of silica from TEOS
It depends. if your pH is really high, silicate $\ce{SiO3^2-}$ or $\ce{SiO4^4-}$ ions will form and will become a stable dissolved solute in the solution. if it is moderately high the rate of hydrolysis will increase greatly and the silicon will crash out in the form of orthosilicate hydrates [$\ce{Si(OH)4}$], which may agglomerate to form silica particles. These results are a bit of a spectrum and there is no pH limit where the reaction gives a binary change in result, as it is also sensitive to extrinsic properties of the solution such as the amount of base.