New fluorescent pH indicators for characterizing cement carbonation
- 发表刊物：Construction and Building Materials
- 关键字：Fluorescent indicators
Carbonation
Reinforced concrete
- 摘要：Fluorescent indicators of a wider labeling pH range of 7.0–12.5 were prepared to characterize the pH evolution of
the accelerated/natural carbonation of cement and the corrosion of steel bar. Compared with conventional indicators (phenolphthalein, pH range of 8.2–8.5), these indicators indicate multiple pH-induced switches of
different fluorescence emissions for the fluorescence resonance energy transfer between donor–acceptor. The
results showed that the newly-developed indicators are sensitive and applicable for labeling both natural and
accelerated carbonation of cement. Investigations by Fourier Transform infrared spectroscopy, X-ray diffraction,
scanning electron microscopy, and thermogravimetric analysis demonstrated the reliability of these indicators,
that is, in the “uncarbonated area” shown by phenolphthalein, carbonization actually occurs as exhibited by
fluorescent indicators. Furthermore, electrochemical impedance spectroscopy, as well as dynamic potential
polarization studies showed that rusting/corrosion of reinforcing steel started when the pH dropped to 11.5 in
the simulation study. This work promoted the contribution of fluorescent indicators in cement carbonation
characterization, with a wide pH response.
- 论文类型：SCI
- 是否译文：否
- 发表时间：2023-05-11
- 收录刊物：SCI
