Thermally stable and fast responsive mesoporous cresol red functionalized silica and titania nanomatrices: Fiber optic pH sensors
Document Type
Article
Publication Date
9-1-2021
Abstract
Owing to the fast responsive fiber optic pH sensing, silica nanomatrix (SNM) and titania nanomatrix (TNM) are synthesized by the sol-gel method at low temperatures. Cresol red (CR) is immobilized within SNM and TNM for sensing evaluation. Crack-free, crystallinity and porous surfaces with an average particle size of CR-SNM similar to 45 +/- 0.4 nm and CR-TNM similar to 24 +/- 0.4 nm are observed through microscopic analysis. The is observed in CR immobilized matrices. The CR-SNM shows lower roughness similar to 7 nm, a large surface area similar to 380 m(2)/g, thermal stability at <= 400 degrees C, and a refractive index 1.47. Whereas, CR-TNM revealed high roughness 48 nm, surface area 211 m(2)/g, and refractive index 1.76. The sensitivity of the CR-SNM coated fiber is estimated at around 52.8 counts/pH which is greater than CR-TNM coated fiber sensitivity 14.53 counts/pH. Moreover, CR-SNM shows response time 0.17 s at pH 12 which is faster than CR-TNM time response 0.48 s. GRAPHICS] .
Keywords
Cresol-red, Silica nanomatrix, Titania nanoparticles, Sol-gel, Fiber optic pH sensing
Divisions
sch_ecs
Funders
Fundamental Research Grant Scheme by Malaysia Ministry of Higher Education (R.J130000.7854.5F191),Fundamental Research Grant Scheme by Malaysia Ministry of Higher Education (FRGS/1/2019/STG02/UTM/02/7)
Publication Title
Journal of Sol-Gel Science and Technology
Volume
99
Issue
3
Publisher
Springer Verlag
Publisher Location
ONE NEW YORK PLAZA, SUITE 4600, NEW YORK, NY, UNITED STATES