Real-Time Monitoring of Gas-Phase and Dissolved CO₂ Using a Mixed-Matrix Composite Integrated Fiber Optic Sensor for...

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Accurate carbon dioxide (CO2) detection is crucial for safe carbon storage.
• Fiber optic (FO) sensors offer field-deployable, real-time monitoring solutions.
• Existing sensors face challenges with humidity and interference from other gases.

Purpose of the Study:

• To develop a novel mixed-matrix composite fiber optic (FO) sensor for CO2 detection.
• To achieve reliable sensing of both gas-phase and dissolved CO2.
• To ensure sensor stability and minimize interference in realistic environmental conditions.

Main Methods:

• Integrated a mixed-matrix composite coating onto an FO sensor.
• The coating comprised plasmonic nanocrystals and hydrophobic zeolite in a polymer matrix.
• Tested sensor performance for CO2 detection in various concentrations, humidity levels, and in the presence of other gases.

Main Results:

• The FO sensor demonstrated high sensitivity and reversibility for CO2 detection.
• The sensor maintained stability in high humidity, mitigating water vapor interference.
• Successfully detected CO2 in the presence of geologically relevant gases and in natural water samples.

Conclusions:

• The developed mixed-matrix composite FO sensor reliably detects gas-phase and dissolved CO2.
• The sensor exhibits excellent stability, sensitivity, and resistance to humidity.
• This technology is a promising candidate for practical CO2 monitoring in carbon storage applications.