LUMINESCENCE STUDIES OF CERIUM(III) INCORPORATED IN SILICA GELS PREPARED USING SOL-GEL METHODS

摘要

Sol-gel methods have been adapted for the incorporation of cerium(III) into a silica gel network, and the resulting gels have been prepared either with or without the use of formamide as a drying control chemical additive (DCCA). The use of formamide and Ce(III) has been found to result in lanthanide-assisted hydrolysis of the amide, leading to crystallization phenomena during gelation. We describe strategies to avoid this, as well as the results of luminescence studies on the Ce/silica gels. The latter have been used to observe the characteristic luminescence of gel-supported cerium, and have also been employed as a probe of the gelation process. This has been found to lead to increasing luminescence intensity, with the most significant increases occurring after gelation and-during the drying stage. [References: 80]