Photo-Sensitive RAFT-Agents for Advanced Microparticle Design

Kaupp, Michael, Tischer, Thomas, Hirschbiel, Astrid F., Vogt, Andrew P., Geckle, Udo, Trouillet, Vanessa, Hofe, Thorsten, Stenzel, Martina H., & Barner-Kowollik, Christopher (2013) Photo-Sensitive RAFT-Agents for Advanced Microparticle Design. MACROMOLECULES, 46(17), pp. 6858-6872.

View at publisher


The current contribution describes the combination of an efficient reversible deactivation radical polymerization process (reversible addition–fragmentation chain transfer (RAFT) polymerization) with a mild light-induced modular ligation technique. A novel RAFT-agent was synthesized which carries a photoactive group based on ortho-quinodimethane (photo-enol) chemistry. The novel photoreactive RAFT-agent controls the polymerization of a wide range of monomers such as styrene, N,N-dimethylacrylamide and a protected glycomonomer (2-(2′,3′,4′,6′-tetra-O-acetyl-β-d-mannosyloxy)ethyl acrylate) with dispersities between 1.07 and 1.17 (3500 g·mol–1Mn ≤ 10100 g·mol–1) and quantitative end-group functionalization. The photo-enol group reacts with dieneophiles under mild irradiation (λmax = 320 nm) at ambient conditions – so that the RAFT-group remains intact – and without any catalyst to form block copolymers in a matter of minutes. Furthermore, the RAFT-polymers can be photografted onto porous polymeric (poly(glycidyl methacrylate)) microspheres, after a one-step prefunctionalization with maleimide moieties. The successful photografting is evidenced by scanning electron microscopy (SEM), elemental analysis (EA), X-ray photoelectron spectroscopy (XPS) and high resolution attenuated total reflectance (ATR) FT-IR microscopy, which leads to qualitative as well as quantitative grafting data. The grafting densities obtained for polystyrene are close to 0.11 chains per nm2 (Mn = 3900 g·mol–1) and for poly(N,N-dimethylacrylamide) close to 0.12 chains per nm2 (Mn = 3500 g·mol–1). To highlight the additional benefit of employing a light-induced grafting reaction, Janus microspheres were prepared with poly(N,N-dimethylacrylamide) employing a Pickering emulsion approach and illustrated via ATR-FT-IR microscopy.

Impact and interest:

23 citations in Scopus
25 citations in Web of Science®
Search Google Scholar™

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 97118
Item Type: Journal Article
Refereed: Yes
DOI: 10.1021/ma401242g
Divisions: Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > Institutes > Institute for Future Environments
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Deposited On: 07 Sep 2016 06:04
Last Modified: 08 Sep 2016 05:02

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page