Kinetic Study on Termination of Living Radical Polymerization:

As in free radical polymerization, the propagating species in living radical polymerization (LRP) is a free radical. Therefore, radical-radical bimolecular termination should unavoidably occur also in LRP and play an important role, giving unique features to its kinetics. This must also be the case with successful LRP systems producing low-polydispersity polymers. In spite of such theoretical considerations, termination in LRP was not correctly understood when she began to study LRP, because of the lack of direct experimental evidence. Thus she directly observed termination reactions in LRP by conducting a monomer-free model experiment and confirmed the occurrence of termination with the same rate constant k_t in LRP as in FRP. Also she made quantitatively experimental tests of the kinetic theories on the polymerization rate and polydispersity for LRP.

Protein Repellency of Well-defined Well-controlled Concentrated Polymer Brushes obtained by Surface-Initiated Living Radical Polymerization:

Surface-initiated LRP provides a well-controlled well-defined polymer brush with high graft density, which is called a "concentrated" polymer brush. The graft density of the concentrated brush is more than one order of magnitude higher than that of the semi-dilute/dilute brushes obtained by conventional methods. In good solvent, this concentrated brush is highly stretched, nearly to their full length. Reflecting this stretched structure, this brush shows strong repulsion against compression and super-lubrication. Focusing on the unique high-extension structure of the concentrated brushes, she revealed the unique size-exclusion effect of the concentrated brushes, namely a good correlation between the protein size and the threshold graft density beyond which the protein does not adsorb. She also confirmed that the interaction of the concentrated PHEMA brush with proteins is very low at the outermost surface but significant inside. She successfully demonstrated that the concentrated brush exhibited excellent protein repellency due to the unique size-exclusion effect. The concentrated brush is believed to be a novel biocompatible surface.