A temperature-responsive carbon black nanoparticle prepared by surface-induced reversible addition–fragmentation chain transfer polymerization

A reversible addition–fragmentation chain transfer (RAFT) agent, 2-{[(dodecylsulfanyl)carbonothioyl]sulfanyl}propanoic acid (DSCTSP), was immobilized on the hydroxyl-functionalized carbon black (CB) surface via a direct condensation reaction, producing CB–DSCTSP. Then, RAFT polymerizations were carried out on carbon black surface using the CB–DSCTSP as a chain transfer agent. Poly(N-isopropylacrylamide) (PNIPAAm) chains were grown from the carbon black surface by a surface-induced reversible addition–fragmentation chain transfer (SI-RAFT) polymerization. FT-IR, 1H NMR, TGA, TEM, and dynamic light scattering were used to characterize the carbon black grafted with poly(N-isopropylacrylamide) (CB-g-PNIPAAm). Dispersion experiment showed that CB-g-PNIPAAm had a good solubility in water. 1H NMR, AFM and dynamic light scattering measurements showed that CB-g-PNIPAAm behaved a reversible temperature-responsive property in water.