Optically active-thermally stable multi-dyes encapsulated mesoporous silica aerogel: A potential pH sensing nanomatrix
Owing to the pH sensing applications, a mixture of four pH dyes (phenol red, bromophenol blue, creosol red, and phenolphthalein) is encapsulated in mesoporous silica aerogel by sol-gel method. FE-SEM analysis shows that dyes have great influence on the morphology of silica matrix. After encapsulatio...
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| Main Authors: | , , , , , |
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| Format: | Article |
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Elsevier B.V.
2019
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| Subjects: | |
| Online Access: | http://eprints.utm.my/id/eprint/88216/ http://dx.doi.org/10.1016/j.micromeso.2018.07.049 |
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| Summary: | Owing to the pH sensing applications, a mixture of four pH dyes (phenol red, bromophenol blue, creosol red, and phenolphthalein) is encapsulated in mesoporous silica aerogel by sol-gel method. FE-SEM analysis shows that dyes have great influence on the morphology of silica matrix. After encapsulation, silica aerogel matrix has low surface roughness ∼ 1.76 nm, ultra-thin layer 8.26 nm, high surface area of 433 m2/g, high optical transparency 77%, low refractive index ∼1.37 at 550 nm and thermally stable. The sensor response is optimized at pH 1–12 with the high value of pKa ∼8.35 at 565 nm without any leaching traces. The fast response time 0.71s in acidic medium (pH 1) and 0.36 s in basic medium (pH 12) is observed. From experimental findings, it can be concluded that fusion of sol-gel and nano-technologies can thus open a new way to synthesize thermally stable, high quality nano-porous optical material for sensing applications at dynamic pH range. |
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