Modification of silica gel is achieved by tetraethyl ortho-silicate (TEOS) preliminary hydrolyzed at room tempera-ture.
TEOS (10 mL) is hydrolyzed with distilled water in a TEOS: water ratio of 1:3.
Hydrolysis proceeds at pH 3: 5-amino-1,3,4 thiadiazole-2-thiol in an amount of 1.0 g is dissolved in 10 mL dimethylformamide (DMFA) and is added, with continuous stirring with a magnetic stirrer, to the hydrolyzed TEOS.
The stirring continues for 3 h at room temperature to the complete homogenization of the solution.
The solution thus obtained is dried for 24 h at 373 K.
In this way, the organic substance is expected to participate in the formation of the porous texture of the sorbent obtained, affecting at the same time the formation of the globular skeleton, i.e., the aggre-gation process.
A powdery sample (S5A) is obtained, washed with distilled water and dried at 373 K.
Pure silica gel (sample SG) is obtained by the classical sol gel method using
the same conditions and initial component ratios