Synthesis of polystyrene microspheres towards the new route of radiolabelling strategy

Identifier:  TFG:10083

Handle: https://hdl.handle.net/20.500.11797/TFG10083

Authors:  Anglada Núñez, Alba

Abstract:
Polystyrene microspheres of 1 and 10 microns were successfully synthesized by a two-step polymerisation method. Firstly, the seeds (Dn, 0.97 µm) were prepared via chain-growth free radical dispersion polymerisation, with benzoyl peroxide as initiator in ethanol-water medium in the presence of poly(acrylic) acid as stabilizer. Secondly, in the presence of the monodisperse (Dw/Dn, 1.08) polystyrene seed particles, two alternative preparation strategies were evaluated differing in the phase, aqueous or organic, used to disperse the seed particles. In both, the seed dispersion was mixed with an ethanol-water solution dissolving styrene, BPO as initiator, and poly(vinyl) alcohol as stabilizer. By slow, continuous, addition of water at a rate of 2.88 mL/h into the mixture, the PS particles absorbed the styrene and swelled up to ca.10 µm. Despite multiple efforts to maintain size uniformity, a loss of monodispersity was observed. Nevertheless, the surface of the PS seed particles was successfully functionalised by UV irradiation under different exposure times.