Yuji Higaki,* Honoka Toyama, Takumi Masuda, Shingo Kobayashi, Masaru Tanaka
"Microphase Separation of Double-Hydrophilic Poly(carboxybetaine acrylate)-Poly(2-methoxyethyl acrylate) Block Copolymers in Water"
Polymer Journal, in press DOI: 10.1038/s41428-023-00831-3
What microphase separation behavior does double hydrophilic diblock copolymers composed of a water-soluble zwitterionic polymer, poly(carboxybetaine acrylate) (PCBA2), and a hydrophilic but water-insoluble nonionic polymer, poly(2-methoxyethyl acrylate) (PMEA), exhibit?
Well-defined PCBA2-b-PMEA block copolymers were synthesized by the reversible addition-fragmentation chain transfer polymerization of carboxybetaine acrylate modified with a tert-butoxy carbonyl group and 2-methoxyethyl acrylate followed by tert-butoxy carbonyl group cleavage. PCBA2-b-PMEA produced particles in dilute aqueous solutions and microphase-separated structures in concentrated aqueous solutions. The hydrodynamic radius of gyration of the particles and the microphase-separated structure were associated with the block copolymer composition and degree of polymerization of the PMEA chain. The molecular assembly behavior was tolerant to NaCl concentration, providing molecular design guidelines for use of double-hydrophilic microphase-separated compartments in physiological environments.
Honoka Toyama was in charge of this project. She is able to discipline herself strictly and continue to work hard. She tackled vigorously the new-type block copolymer synthesis through try and error cycles and achieved the synthesis. She also performed SAXS experiments at synchrotron radiation facility and organized the data. I love her earnest personality, which sometimes makes me worry about. I hope her health and success in her new journey in graduate school.
Takumi Masuda supported the research as a mentor. He carefully took care Honoka in chemical experiments and structural analysis, also guided her in research planning and document preparation. I am convinced that this research would not have been successful without his help.
This is the collaboration work with Prof. Masaru Tanaka and Prof. Shingo Kobayashi in Kyushu University, with support from the Cooperative Research Program of “Network Joint Research Center for Materials and Devices”. We sincerely appreciate their support and advice on this research.
