Microfluidic Synthesis of Macroporous Copolymer Particles
Stanislav Dubinsky1, Hong Zhang1, Zhihong Nie1, Ilya Gourevich1, Dan Voicu1, Eugenia Kumacheva1, and Martin Deetz2. (1) Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada, (2) Advanced Biosciences, Rohm and Haas Chemicals, LLC, 727 Norristown Road, Spring House, PA 19477-0904
Macroporous polymer resins are a class of materials with a permanent well-defined porous structure. A broad range of applications of these polymers(ion exchange, catalysis,biomedical applications)requires a “tailor-made” particle/pore size and particle/pore size distribution. A method that yields monodispersed macroporous particles with dimensions in the range from 50 to 100 micrometers and controlled distribution of the size of pores is highly desirable.The ability to generate porous particles by means of microfluidic synthesis has been demonstrated,however, currently no thorough study exists on the formation of macroporous particles with pre-determined dimensions and controlled pore size distribution. Here,we report semicontinuous photoinitiated microfluidic synthesis of macroporous polymer particles with a narrow size distribution in the size range from tens to hundred microns. The microbeads were synthesized by (i) emulsification of the mixture of glycidyl methacrylate (GMA), crosslinking agent and porogen in the microfluidic droplet generator; (ii) on-chip photopolymerization of GMA and (iii) off-chip post-photopolymerization of GMA. The use of GMA was motivated by the ability to carry out subsequent surface modification of the resulting microbeads, due to the reactivity of the pendant epoxide groups. Combination of the advantages of conventional suspension polymerization and microfluidic synthesis allowed us to produce polymer particles with a narrow size distribution and a controlled size of pores.