The following materials were used:tetraethylorthosilicate (TEOS) (Purity 95%) was
supplied by Ibn Sina state Co. and then redistilled twice in our laboratory; Ethanol was of Analytical grade (Purity 99.9%) supplied by Gainland Chemical Company, U.K.; Rhodamine 101
(molecular weight 591.06 gm/M Lc (6400)); Rhodamine 6G (molecular weight 479.02 gm/M Lc
(5900)); and Coumarin 153 (molecular weight 309.29 gm/M, Lc (6400)), all supplied by Lambda
physik [7]. Fig. 2 shows the chemical structure of these dyes