Facile and large-scale synthesis of poly(m-phenylenediamine) microparticles with interesting hollow morphology

Hollow poly(m-phenylenediamine) (PmPD) microparticles were successfully synthesised with chemically oxidative polymerisation through rapidly mixing the persulphate oxidant solution with m-phenylenediamine solution at room temperature. In a further experiment, Na₂CO₃ was used to create a CO₂ bubble to facilitate the formation of hollow PmPD microparticles. The morphology and molecular structure of the products were characterised with scanning electron microscopy, transmission electron microscopy and Fourier transmission infrared spectroscopy. The results showed that the PmPD possesses a mouth-like cave when synthesised without Na₂CO₃. More interestingly, using Na₂CO₃, the cave number and shape of PmPD microparticles change. The PmPD synthesised with or without Na₂CO₃ has similar functional groups but different oxidation state.