Controlled Synthesis of Polymer Micro- and Nanoparticles Stained with Luminophores and Analysis of the Resulting Particle Surface Functionalities and Luminescence Properties

Abstract

This work is focused on systematic studies of the correlation between the morphology of semiconductor nanoparticles (NPs), their luminescence properties and the application relevant features of polymer microparticles (PMPs) stained with these NPs. The synthesis of luminescent, quantum dot (QD)-stained polystyrene microparticles (PSMPs) was first developed and optimized for CdSe/CdS-QDs, which was later expanded to quantum rods (QRs) and nanoplatelets (NPLs) of the same composition. Apart from nanoscale luminophores, the organic dye Nile red has been employed. While the incorporation of dyes is comparatively easy and well studied, the use of luminescent NPs such as QDs often goes along with challenges such as NP aggregation or excessive loss of fluorescence intensity, which were addressed in this work. Additionally, a systematic investigation of nanoscale, core/shell-type luminophores of different shell thicknesses, materials/composition and shapes before, during and after the PSMP synthesis was performed to deduce a connection of NP architecture with their applicability for the synthesis. The work also includes the introduction of surface functional groups (carboxy) to the PSMP surface, and evaluates the influence of the exact synthesis route on the properties of the formed particle, comparing NP addition before the polymerization and incorporation by a postsynthetic swelling procedure.