Fabrication of hierarchical porous polymer particles via blending strategy of water and polymer mixture

Hierarchical porous polymer particles (HPPPs) from the assembly of polymer chains have attracted increasing interest because of their prospective applications in drug delivery and catalysis. This work utilized a blending strategy of polymer mixture in mixed solvents to fabricate HPPPs with adjustable pore structures. Firstly, using methacrylic acid (MAA) and methyl methacrylate (MMA) with a precise ratio, a copolymer solution of P(MMA-MAA) was prepared in a mixed solvent of ethanol and water. Then, styrene (St) was added stepwise along with polymerization for achieving a translucent polymer mixture. Further, a quantitative amount of the polymer mixture and six-fold volume of water were rapidly mixed with vortex oscillation. The HPPPs were formulated eventually by the assembly of hydrophilic P(MMA-MAA) copolymers and hydrophobic PSt homopolymers, as well as micelles comprised of P(MMA-MAA) copolymer and low-polarity solvent. The size and number of nanopores were effectively regulated by the solvent polarity, polymerization temperature and monomer ratios. Moreover, the resultant HPPPs exhibited a hierarchical porous structure, having broad application in biomedical and environmental sciences. (c) 2022 Society of Industrial Chemistry.