Fabrication of mesoporous crystalline microparticles of poly(ether sulfone) via solvent-induced crystallization

Mesoporous polymer microparticles are promising for energy, environmental, and biomedical applications. A linear polymer microparticle is desirable from the perspective of polymer recycling. In this study, mesoporous crystalline microparticles of a commercially available high-performance polymer, poly(ether sulfone) (PES), were prepared. Solvent-induced crystallization of PES in nitrobenzene resulted in nearly spherical microparticles with an average size of 5 mu m and narrow size distribution. The microstructure and mesoporosity of the microparticles were characterized with scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and nitrogen adsorption/desorption, which gave a pore size distribution peaking at 7 nm with a porosity of 0.44. Fourier-transform infrared spectroscopy, Raman spectroscopy, and thermogravimetric analysis confirmed the cocrystal of PES and nitrobenzene. The formation mechanism of the PES microparticles was elucidated based on the theory of polymer spherulite formation. This study gives an insight on solvent-induced crystallization of rigid high-T, polymers useful for the mesoporous polymer particle fabrication.

Automated summary

This study successfully prepared mesoporous crystalline microparticles of a commercially available high-performance polymer, poly(ether sulfone) (PES), and characterized their microstructure and mesoporosity. The formation mechanism of PES microparticles was elucidated, providing important insights for the fabrication of mesoporous polymer particles.