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Common problems and solutions in the emulsification process of microemulsion are as follows:
- 1. System stability problem Turbidity after dilution
- Phenomenon:
- W/O type microemulsion changes from transparent to milky white after dilution Reason: Dilution destroys the critical micelle concentration (CMC) of the surfactant, resulting in the disintegration of the microemulsion structure .
- Solution: Optimize the surfactant compound ratio, or use an emulsifier with a more matching HLB value Gelation.
- Phenomenon: Viscous gel state appears during the preparation process .
- Reason: The emulsifier ratio is too high or the oil-water ratio is improper .
- Solution: Adjust the amount of co-surfactant (such as short-chain alcohol) added, or change the order of addition.
- 2. Process control issues
- Difficulty in judging critical points
- Phenomenon: It is difficult to determine the key parameters for the formation of microemulsions.
- Solution: Conductivity measurement or microscopic observation of the phase change process .
- Temperature sensitivity
- Phenomenon: Temperature fluctuations lead to changes in system turbidity .
- Solution: Maintain a constant temperature of 40-60°C to avoid exceeding the surfactant cloud point.
- 3. Verification and Remediation Rapid Detection Method:
- Centrifugal test (3000rpm/30min) Verify stability Laser particle size analyzer detects whether the particle size is in the range of 10-100nm.
- Demulsification treatment: Add ethanol or adjust pH value to destroy the interface film and add high HLB value emulsifier to achieve phase inversion.
Note: All solutions need to be optimized and adjusted based on the specific formula system.