Synthesis of Low‐Surface‐Energy Fluorinated Microemulsions by High‐Pressure Homogenization Processing Using Thermally Decomposable Amphoteric Surfactants

ABSTRACT In this paper, fluorinated microemulsions with small particle size, good stability, and low surface energy were successfully prepared by using high‐pressure homogenization processing for the dispersion of monomers and thermally decomposable N‐dodecyl‐N, N‐dimethylamine N‐oxide (LDAO) as surfactant. The synthesized products were determined to be fluorinated terpolymers using FTIR, 1 H NMR, and GPC. The effect of homogenization processing and LDAO on the synthesis of the emulsions was investigated by determining the monomer conversion rate, emulsion particle size, mechanical stability, and surface energy. The results showed that when the homogeneous pressure was 45 kPa, the pH value was 2, and the LDAO concentration was 2%, the fluorine microemulsion with 98.9% monomer conversion, 61.7 nm particle size, good centrifugal stability, and 9.3 N m −1 surface energy could be produced. Common substrates became superhydrophobic (or strongly hydrophobic) and oil repellent after modification by prepared microemulsion. The modified substrates have excellent corrosion resistance and lower water absorption (water absorption value of only 1.3%). In addition, the coatings prepared in this paper are more difficult to be wetted by NaCl solution compared to coatings prepared with conventional fluorinated emulsions. It has great potential for application in the preparation of long‐life and corrosion‐resistant surfaces.