Behavoir of Trapped Bromothymol Blue into Sol-Gel Matrix in Presence of CTAB

Encapsulation of bromothymol blue (BTB) into a polysiloxane network was prepared using sol-gel method without using a catalyst. The co-entrappment of the bromothymol blue (BTB) and surfactant cetyltrimethyl ammonium bromide (CTAB) was used to modify the properties of the sol-gel matrixes which may provide a highly porous materials and made the polysiloxane network an excellent host for sensing molecules. Monolithic disks of trapped BTB were obtained with no leaching. Polarized light microscopy shows that a almost unique particle sizes distributions were formed. The immobilized BTB shows a response for various pH solutions, the feature of absorption spectra of the immobilized BTB was almost the same as that of the solutions.