1) Preparation of photoactive polymer colloids by Polymerization‐Induced Self‐Assembly (PISA): core-shell type polymer latexes synthesized by polymerization in dispersed alcoholic media are designed. As the photosensitizer molecule, the nontoxic and commercially available Rose Bengal (RB) dye was chosen. The formation of photo-active polymer colloids was consisting of 3 steps (image 1):
- Synthesis of PSens-based polymerizable methacrylate monomer (EMARB) involving RB group
- Controlled copolymerization, by reversible addition fragmentation chain transfer (RAFT) polymerization, of a hydrophilic monomer such as oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and EMARB dye based comonomer which led to formation of the hydrophilic part called macromolecular chain transfer agent.
-Employing PISA in dispersion that led to create amphiphilic core-shell colloids. The objective in this step was to locate the PSens in the stabilizing hydrophilic shell and the insoluble hydrophobic polymer such as polybenzyl methacrylate (PBzMA) in the core.
This class of photoactive polymer colloids dispersed in alcoholic continuous phase offered additional perspectives for the 2nd objective of APOCOLIPs in terms of applications, ie the process intensification via LED-driven continuous-flow microphotoreactors for photooxygenation of fine chemicals (collaboration with CNRS LGC France).
2) Stable photo-active core-shell submicronic polymer colloids in aqueous dispersed media were also synthesized using completely different monomers and reaction conditions.
3) The photoactivity of polymer colloids was evaluated for singlet oxygen (1O2) production in collaboration with a PhD student. The quantum yield of singlet oxygen production was measured using an indirect method based on the photo-oxidation kinetics of a quencher molecule. As result, these photoactive colloids efficiently produced singlet oxygen at the particle/alcohol interface under visible light irradiation. The average quantum yield of singlet oxygen production approached that of free RB.
4) Results from APOCOLIPS led to collaboration with Laboratoire de Génie Chimique (INP, CNRS, France) and ongoing research related to this subject is being conducted involving the dedicated work of 2 PhD students.
5) The project results were disseminated through manuscript preparation and participation in some scientific conferences such as:
- ECIS 2022 conference, 4 -9 September 2022, Chania, Crete, Greece
- SCM10 conference, 1-3 February 2023, Amsterdam, Netherlands
- APME23 conference, 23-27 April 2023, Paris, France
6) The fellow had the opportunity to co-supervise a master student during his fellowship.
