How should the isolation fluid be selected for a material system that is in contact with both halogenated hydrocarbons and hydrofluoric acid?

When selecting an isolation fluid, factors such as its chemical stability toward halogenated hydrocarbons and hydrofluoric acid, physical stability (such as boiling point and freezing point), safety (non-flammable and non-explosive), and environmental friendliness need to be considered. Commonly used isolation fluids in the industry today include silicone oil, mineral oil, and fluorinated liquids. Silicone oil is the preferred choice in most cases due to its good stability, but because its stability against hydrofluoric acid is insufficient, other types of insulating fluids may need to be considered. Especially under high temperatures or pressures, silicone oil may degrade. Mineral oil also has relatively good stability, but oxidation problems may occur under high temperature and pressure conditions. Fluorinated liquids, such as oligofluorosilanes, have good stability toward hydrofluoric acid and can be considered as isolation fluids. However, due to the high cost of fluorinated liquids, from an economic perspective, it may be necessary to consider using them in combination with other isolation fluids such as silicone oil and mineral oil. At the same time, attention must also be paid to the ecological and environmental issues associated with fluorinated liquids. In summary, it is recommended to first try using silicone oil or mineral oil to see if they can meet the requirements for system stability. If this requirement cannot be met, consider using a fluorinated liquid, or adopt a strategy that combines silicone oil with a fluorinated liquid. Of course, the specific details need to be carefully evaluated and determined based on the specific conditions of the system (such as temperature, pressure, fluidity, pipe material, etc.). .