Rapid synthesis of fluorescent single-chain nanoparticles via photoinduced step-growth polymerization of pendant carbazole units

Publication date: 15 February 2020Source: European Polymer Journal, Volume 125Author(s): Deniz Kilic, Ceren Pamukcu, Demet Karaca Balta, Binnur Aydogan Temel, Gokhan TemelAbstractAn easy and rapid strategy is developed to synthesize light responsive single-chain nanoparticles via photoinduced radical coupling of carbazole moieties in the side chain of polymer. Firstly, nitroxide-mediated radical polymerization is carried out for the synthesis of chloride functional styrenic copolymer. Pendant chloride groups of the polystyrene copolymer are converted to carbazole units by one-step modification. Constructed functional polymer undergoes photochemically intramolecular crosslinking using carbazole step-growth polymerization. Size of the nanoparticles can be manipulated by changing the degree of polymerization which is dependent to the dose of UV exposure. Achieved single-chain nanoparticles exhibit higher glass transition temperatures and lower hydrodynamic radii compared to their linear analogue. Polymeric nanoparticles are successfully employed for the cyclohexane oxide polymerization as cationic photoinitiators in the presence of an iodonium salt.Graphical abstractSingle chain nanoparticles via photoinduced intramolecular crosslinking of pendant carbazole species are presented. Step-growth polymerization of side-chain carbazole motifs causes collapsing polymer chains upon UV-light exposure and degree of crosslinking can be manipulated by increase of irradiation time.
Source: European Polymer Journal - Category: Chemistry Source Type: research