| Popis: |
We present an argument that common, commercially available laboratory benchtop pH meters can be used to determine the acidity of tetraethlyorthosilicate(TEOS)-water-ethanol systems used to prepare silica xerogels. Using an acidity scale for such systems which appears in the electrochemical literature, we demonstrate the correlation between acidity and three properties of TEOS-water-ethanol silica gel systems : gelation time, syneresis induction time, and xerogel pore structure as determined by nitrogen sorption. We show that the correlation between acidity and properties in these systems closely resembles the same correlations documented in aqueous silica gel systems. |
