Synthesis of amphiphilic fluorinated copolymer and the formation of hollow nanotubes

Amphiphilic fluorinated block copolymers are prepared via the two-step reversible addition-fragmentation chain transfer polymerization (RAFT), and micelles with well-defined core–shell morphology can be observed in the soap-free aqueous emulsion by transmission electron microscopy (TEM). By adding a relatively excessive amount of initiator, free radical polymerization also happens, and a small amount of hydrophobic homopolymers are produced, which exist in the hydrophobic core. After extracting homopolymers in the core by adding a certain amount of benzotrifluoride into the diluted emulsion, drastic changes in the morphology and stability of fluorinated block copolymers aggregate were observed. First, cross-link and aggregating of the micelles was observed; second, by stirring for a further 50 min, hollow nanotubes can be produced.