Highly CO2 sensitive extruded fluorescent plastic indicator film based on HPTS

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Carbon dioxide (CO2) detection is crucial for environmental monitoring and industrial processes.
• Optical fluorescent sensors offer high sensitivity and selectivity for gas detection.
• Developing stable and versatile CO2 sensing materials remains an active area of research.

Purpose of the Study:

• To develop highly sensitive optical fluorescent extruded plastic films for CO2 detection.
• To investigate the CO2 sensing performance of these films in both gaseous and dissolved states.
• To evaluate the stability and practical applicability of the developed CO2 sensing films.

Main Methods:

• Fabrication of an 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) pigment with fumed silica and tetrabutylammonium hydroxide.
• Extrusion of the HPTS pigment powder into low-density polyethylene (LDPE) to create CO2-sensitive plastic films.
• Characterization of the optical (luminescence and absorbance) and response properties of the HPTS pigment and plastic films to varying CO2 concentrations.

Main Results:

• The HPTS pigment exhibited high CO2 sensitivity (%CO2 (S = 1/2) = 0.16%) with rapid response (2 s) and recovery (5 s) times.
• The extruded HPTS-LDPE plastic films demonstrated high CO2 sensitivity (%CO2 (S = 1/2) = 0.29%) for gaseous CO2.
• The plastic films showed slower response (<2 min) and recovery (<40 min) times compared to the pigment but maintained stability (>six months) and detected dissolved CO2 in various aqueous media.

Conclusions:

• Highly sensitive and stable optical fluorescent plastic films for CO2 detection have been successfully fabricated.
• The developed HPTS-LDPE films offer a promising platform for sensing both gaseous and dissolved CO2 in diverse environments.
• The material's stability and ability to detect dissolved CO2 in aqueous solutions highlight its potential for practical applications.