Effects of the addition of electrolyte on liquid infiltration in a hydrophobic nanoporous silica gel

In this letter, we report the experimental results of pressure induced infiltration in the hydrophobic nanopores of a silica gel. The infiltration pressure increases with the prolonged surface treatment time, whereas the infiltration volume is not dependent on the surface coverage. When temperature increases, if the liquid phase is pure water, the infiltration pressure would decrease, which is in agreement with the classic contact angle measurement results at large solid surfaces. As an electrolyte is added, however, the variation in infiltration pressure is negligible over a broad temperature range. © 2008 American Chemical Society.