This article is a report about the novel fluorescence temperature sensor based on a surfactant-free Poly (vinly alcohol)/borax/2-naphthol hydrogel system. The well-known fluorescence indicator, 2-naphthol, exhibits a change of fluorescence intensity when it is embedded in aqueous PVA/borax gel networks at various temperatures. The blue color emission intensity(PL: λmix = 426 nm) of 2-naphthol in a basic hydrogel changed gradually to strong from 30°C to 80°C when excitation wavelength was 365 nm. The pH change in the hydrogel system was in the range from 8.50 at 30°C to 9.35 at 80°C with rising temperature. In the case of salicylic acid, the blue color emission intensity in the acidic gel decreases with rising temperature when excitation wavelength was 365 nm in all cases. The pH change in the hydrogel system was from 2.80 at 30°C to 2.40 at 80°C with rising temperature.
- Fluorescence indicator
- Fluorescence temperature sensor