Optical Detection of Water Adulteration in Ethanol Using PCPDTBT-Conjugated Polymer Nanoparticles

Area of Science:

• Materials Science
• Analytical Chemistry
• Chemical Engineering

Background:

• Ethanol biofuel quality is critical, but detecting water adulteration is challenging with conventional methods.
• Ethanol's affinity for water complicates accurate quantification in fuel blends.
• Limitations exist in current analytical techniques for real-time water content monitoring.

Purpose of the Study:

• To develop a novel optical sensing strategy for detecting water in ethanol biofuel.
• To utilize conjugated polymer nanoparticles (CPNs) for sensitive and rapid water quantification.
• To establish a reliable method for assessing biofuel quality and identifying water adulteration.

Main Methods:

• Synthesis of poly-[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta-[2,1-b;3,4-b0]-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) conjugated polymer nanoparticles (CPNs) via nanoprecipitation.
• Characterization of CPNs' optical properties, including dual-emission bands at 679 nm and 846 nm.
• Investigation of CPN response to varying water concentrations in ethanol blends, monitoring changes in emission intensity ratio (I679/I846).

Main Results:

• CPNs exhibited dual-emission bands sensitive to water-induced aggregation in ethanol.
• A strong linear correlation was observed between the emission intensity ratio (I679/I846) and water concentration.
• Achieved a limit of detection (LOD) of 0.4% (v/v) and a limit of quantification (LOQ) of 1.3% (v/v) for water in ethanol.

Conclusions:

• PCPDTBT CPNs provide a sensitive and practical platform for optical water detection in ethanol biofuel.
• The developed method enables rapid and precise quantification of water content, aiding in biofuel quality assessment.
• This approach holds significant potential for future analytical tools to combat water adulteration in ethanol.