dear Radouane,

the lifetime could depend on several factor.

First of all the dry content (%) and particle size of the sol are relevant factors. Lower the particle size and higher the dry content lower the stability.

Without addition of proper dispersing agents (so only particles and water) you can have problems of sedimentation in particular with high dry content (>30%) and sub-micron average particle size always in a few hours if the solution is static.

Dear Radouane,

TiO2 is very stable. You can have variations in the degree of compaction, but, in general, I would not expect big changes... In fact, some time ago we analyzed some suspensions of TiO2 in water that were 2 years old and were practically equivalent to those recently prepared in the laboratory.

Best,

Fran

Thank you for your responses