Common biocompatible fluorinated oils currently available include Fluo-Oil 7500, 3M Novec HFE7500, Fluo-Oil 135, Fluo-Oil 40, FC40, and Fluo-Oil 200. These oils have a certain degree of breathability and do not cause PDMS material to expand. When biological entities such as cells and bacteria are encapsulated within microspheres formed by these oils, the biological entities can survive. Additionally, using these fluorinated oils can increase the number of times PDMS chips can be used. Mineral oil, silicone oil, and other substances, when in prolonged contact with PDMS chips, can cause the chips to expand, thereby reducing the number of times the chips can be used.
In addition to the commonly used Fluo-Oil 7500, this article provides reference data on the volatility of Fluo-Oil 40, which is useful for professors, researchers, graduate students, and engineers.
Material: Fluo-Oil 40
Temperature: 18°C
Environment: Regular commercial office building
Carrier: CITOGLAS microscope slide
Operating procedure:
Take some Fluo-Oil 40 from the glass bottle and drop it onto a glass slide. Use a stopwatch to time and observe the volatility of Fluo-Oil 40.
Results:
After 10 minutes, the fluorinated oil 40 on the slide has a certain degree of fluidity. When touched by hand, the fluorinated oil 40 is clearly visible, and it has not completely evaporated. When the slide is tilted, the fluorinated oil 40 can be seen flowing clearly.
At 34 minutes, the fluidity of Fluorine Oil 40 on the surface of the slide slowed down. When the slide was manually slid, it adhered to Fluorine Oil 40, indicating that Fluorine Oil 40 had not dried out or completely evaporated.
After 60 minutes, most of the fluorinated oil 40 on the slide had solidified, and a thin film could be seen. At three locations, the fluorinated oil 40 had dried into a film, while at locations 1 and 2, the fluorinated oil 40 had not dried and remained wet and liquid, with the hand able to adhere to the fluorinated oil 40.
Conclusion:
Fluo-Oil 40 does not completely evaporate within 10 minutes at a temperature of 18°C, causing it to dry out and form an adhesive film. Instead, it remains in a liquid state and retains a certain degree of fluidity.
Additional information:
Fluorinated oil FC40:
Boiling point: 165°C
Viscosity: 4.1 mPa*s
Density: 1.85 g/mL
Fluorinated oil HFE7500:
Boiling point: 129°C
Viscosity: 1.24 mPa*s
Density: 1.63 g/mL
Mineral oil:
Boiling point: 218°C
Viscosity: 25-80 mPa*s
Density: 0.84 g/mL (25°C)