Evaluation of air acidity through optical sensors

Area of Science:

• Materials Science
• Environmental Science
• Analytical Chemistry

Background:

• Air pollution, particularly acidifying gases like sulfur dioxide (SO2), poses risks to environmental quality and material preservation.
• Developing cost-effective and sensitive monitoring tools for air acidity is crucial for environmental protection and conservation efforts.

Purpose of the Study:

• To design and produce optical sensors for evaluating air acidity using dye-doped coatings.
• To assess the performance of these sensors through laboratory calibration and field testing in urban environments.
• To establish a correlation between sensor response and SO2 concentration, considering environmental factors.

Main Methods:

• Sol-gel method for fabricating dye-doped coatings for optical sensors.
• Laboratory calibration and field measurements in Cracow, Poland.
• Correlation analysis between sensor optical response, SO2 concentration, relative humidity, temperature, and atmospheric pressure.

Main Results:

• A direct relationship was established between SO2 concentration and the optical response of the developed sensors.
• The sensors demonstrated a detection threshold for pH of approximately 0.05.
• Sensor performance was evaluated under varying environmental conditions, including humid atmospheres.

Conclusions:

• The developed optical sensors are effective analytical tools for monitoring air acidity and SO2 levels.
• These sensors can serve as an early warning system for acid rain risks, particularly beneficial for the preventive conservation of historical materials.
• The sol-gel based optical sensors offer a promising approach for environmental monitoring applications.