A low-cost, accurate, and fast technique to determine the solubility of liquid-liquid mixtures by continuous cloud point titration is demonstrated. A light-emitting diode (LED) is employed to illuminate the mixing liquids during the continuous-flow titration process, and the transmitted light as well as Mie scattering from droplets is monitored using a simple webcam image sensor. The time-resolved evolution of the signal allows the determination of the solubility. In order to prove the concept and to evaluate its accuracy and reproducibility, experimental results from the binary systems butan-1-ol/water and pentan-1-ol/water are presented and compared with literature data. The entire setup can be realized with a low investment and delivers results virtually identical to those in literature with established techniques. The approach is suitable for academic and industrial, but due to its simplicity also for educational purposes.
Royal Academy of Engineering/Exxonmobile Excellence in Teaching Award
Scottish Sensor Systems Centre (SSSC) funded by the Scottish Funding Council
This work was supported through the Royal Academy of Engineering/Exxonmobile Excellence in Teaching Award and the Scottish Sensor Systems Centre (SSSC) funded by the Scottish Funding Council. The authors thank Jan Walker for technical assistance.
- Cloud point
- Continuous titration
- Light-emitting diode
- Mie scattering