One-pot preparation of spherical polycyclic aromatic polymer particles using various aliphatic amines

The synthesis of nano- to microsized spherical polymer particles can be achieved via various methods, however, particle formation methods involving consecutive reactions are scarce. The development of spherical particles ranging from submicron to micron size via the polymerisation of polycyclic aromatic phenols and heterocyclic amines in solution has been reported recently. In this study, spherical polymer particles with polycyclic aromatic polymer backbones were prepared via polymerisation of dihydroxynaphthalene and formaldehyde with various aliphatic amines containing alkyl, carboxyl, and amino groups. The average diameter of the particles varied from 400 to 900 nm depending on the type of aliphatic amine used during preparation. Elemental analysis revealed the presence of nitrogen in all the particles, with the aliphatic amine being incorporated into the polymer backbone. All particles contained C-N-C and (C) 3 -N bonds, indicating that the aliphatic amines contributed to the crosslinking structure. The isoelectric points of the particles were 1.4 (6-aminohexylcarboxylic) and 4.8 (1,6-diaminohexane), demonstrating that carboxyl and amino groups were introduced onto the particle surface. The particles were highly dispersible in various solvents ranging from water to hexane. All the particles adsorbed cationic dyes, indicating that the particle surfaces were negatively charged, with the amount of dye adsorbed varying with the functional groups on the surface. The proposed one-pot method simultaneously enables particle formation and functionalisation, thereby expanding the diversity of the afforded particles and providing more versatile technologies for developing functional spherical particles. • Functional group was facilely introduced into polycyclic aromatic polymer particles. • Process includes polymerisation of dihydroxynaphthalene, aliphatic amine and aldehyde. • Functional groups on the surface of polymer particles depended on the type of amine. • Surface charge and dye adsorption varied depending on functional group introduced.