Functionalization of TiO₂ nanoparticles with semiconducting polymers containing a photocleavable anchor group and separation via irradiation afterward

The controlled radical polymerization (RAFT polymerization) of semiconducting polymers based on poly(4,4′-dimethyl-triphenylamine) is described. These polymers are afterward end-functionalized with a photocleavable group and an anchor unit (catechol) for oxidic nanoparticles (NPs). Serving as a reference, polystyrene oligomers with the same end groups are also synthesized. Using these polymers allows functionalization of the TiO ₂-NPs, leading to an improved solubility and miscibility in organic solvents or polymer matrices. Irradiation in the UV region is used to split the photocleavable group and remove the polymer chains from the NPs, which leads to their aggregation. Controlled radical polymerization (RAFT polymerization) is used to synthesize semiconducting polymers that carry a photocleavable anchor unit for oxidic nanoparticles at the chain ends. These polymers are used to functionalize TiO₂ nanoparticles to improve their solubility and miscibility in organic solvents or a polymer matrix. Irradiation with UV light induces photocleavage and removes the polymer chains from the nanoparticles.