Synthesis and characterization of multilayered sol–gel based plastic-clad fiber optic pH sensor

• Main Authors: Islam, Shumaila, Abdul Rahman, Rosly, Othaman, Zulkafli, Riaz, Saira, Naseem, Shahzad
• Format: Article
• Published: Elsevier B.V. 2015
• Subjects: QC Physics
• Online Access: http://eprints.utm.my/id/eprint/58858/; http://dx.doi.org/10.1016/j.jiec.2014.08.007
• Institution: Universiti Teknologi Malaysia

The fabrication and characterization of an optical fiber pH sensor for the detection range 3-11 are described. The sensing element consists of a combination of indicators encapsulated in mesoporous surfactant based hybrid matrix, which are deposited onto an uncladed plastic optical fiber. Stable, dense and uniform sol-gel cladding with more than 90% transparency in the visible range are observed. Roughness value 9.7-6.57 nm is obtained by AFM. Film thickness, refractive index, and porosity are found to vary with number of coatings, 70% porosity is determined with 116 nm thickness. The response of the sensor with third layer is observed in acid and basic medium.