Encapsulation of Bromocresol Green pH Indicator into a Sol‐Gel Matrix

Abstract

The bromocresol green pH indicator was encapsulated into transparent monolithic silica matrices using acid catalyzed sol‐gel reaction. Tetraethylorthosilicate was used for the entrapment of the bromocresol green indicator. The immobilized bromocresol green shows behavior similar to its solution counterpart. It retains its structure during the sol‐gel reactions in terms of response to pH and albumine. The polarized light microscopy has indicated that the bromocresol green molecules are strongly interacted within the host silica network.

Keywords:

• Bromocresol green pH indicator
• sol‐gel encapsulation
• immobilization of indicators
• polysiloxane entrapment