Binary Polymer Brushes on Silica@Polymer Hybrid Nanospheres and Hollow Polymer Nanospheres by Combined Alkyne-Azide and Thiol-Ene Surface Click Reactions

Silica@polymer core-shell hybrid nanospheres and air@polymer hollow nanospheres with surface-grafted binary polymer brushes were synthesized by a combination of sol gel reaction, distillation precipitation polymerization and dual click reactions (alkyne-azide and thiol-ene click chemistry) Initially, 179 nm silica@poly(methacrylic acid-co-propargyl methacrylate co divinylbenzene) (SiO2@P(MAA-co-PMA-co DVB)) core shell hybrid nanospheres were prepared by distillation precipitation copolymerization of MAA, PMA, and DVB in acetonitrile, using the 151 nm silica nanospheres from sol gel reaction as templates The propargyl groups from PMA and residual C=C double bonds from DVB on the SiO2@P(MAA-co-PMA-co DVB) core shell hybrid nanospheres provided dual clickable functionalities for the respective alkyne-azide and thiol-ene reactions with the azido-terminated hydrophobic polystyrene (PS-N-3 M-n=2550 g/mol) and thiol-terminated hydrophilic poly(ethylene glycol) (PEG SH, M-n = 5000 g/mol) Finally, hairy hollow nanospheres with a hollow core cross linked copolymer shell, and binary polymer brushes on the shell surface were prepared by selective removal of the inorganic silica core from the SiO2@P(MAA coPMA-co-DVB) click-PS/PEG nanospheres in HF solution