Dispersible microporous diblock copolymer nanoparticles via polymerisation-induced self-assembly†
Microporous materials are predominantly formed as insoluble powders which means that they can be difficult to process. Here we report a new class of solvent-dispersible porous polymers synthesised by reversible addition–fragmentation chain transfer mediated polymerisation-induced self-assembly (RAFT-mediated PISA), formed from the polymerisation of divinylbenzene and fumaronitrile using a poly(ethylene glycol) macromolecular chain transfer agent (PEG macro-CTA). The particles have a dual morphology consisting of smaller spheres of 24–29 nm in diameter aggregated into larger particles of 204–262 nm in diameter. Gas sorption analysis showed the particles to have BET surface areas of 274 to 409 m2 g−1 with internal pore sizes centred around 1.8 nm and further larger pores arising from the sphere packing of the aggregates. The particles were found to be photoluminescent (emission λmax = 326 nm) when exposed to UV light which could be quenched by the addition of nitroaromatic compounds, for example, 99% of the emission was quenched in the presence of 38 ppm picric acid.