[Lecture] Seeing the light: PET-RAFT polymerization and 3D and 4D printing system


Title: Seeing the light: PET-RAFT polymerization and 3D and 4D printing system
Speaker: Prof. Cyrille Boyer,The University of New South Wales
Venue: Meeting Room 346, Building No.25, Wushan Campus
Time: December 16, Monday, 15:00

Reversible ddition-fragmentation chain-transfer (RAFT) polymerization is a valuable tool for synthesizing macromolecules with controlled topologies and diverse chemical functionalities. However, the application of RAFT polymerization to additive-manufacturing processes has been prevented due to the slow polymerization rates of typical systems. In this work, we developed a rapid visible light mediated RAFT polymerization process and applied it to a 3D printing system. The photosensitive resins contained a metal-free dye (erythrosin B) in conjunction with a tertiary amine co-catalyst (triethanolamine) and a trithiocarbonate RAFT agent (2-(butylthiocarbonothioylthio) propanoic acid) to afford polymerization without prior deoxygenation. The reaction components are non-toxic, metal free and environmentally friendly (water based photosensitive resin), which tailors these systems toward the fabrication of biomaterials. Following optimization of the resin formulation by varying the ratio of photocatalyst and tertiary amine, a variety of 3D printing conditions were investigated to prepare functional materials using green light (λmax = 525 nm, I0 = 0.32 mW/cm2). Furthermore, the mechanical properties of these 3D printed materials were tested under different conditions. Interestingly, the concentration of trithiocarbonate impacted the mechanical properties and the performance of these materials. Remarkably, the use of a photoinduced polymerization process provided facile spatial control over the network structure by varying the light dose to each layer of the 3D printed material; using this strategy, a 4D printing process was demonstrated via 3D printing and subsequent swelling and dehydration induced actuation. Furthermore, the trithiocarbonate species incorporated in the polymer networks were able to be reactivated after the initial 3D printing process, which enabled post functionalization of the printed materials via secondary photopolymerization processes. This RAFT-mediated 3D and 4D printing process should provide access to a range of new functional and stimuli-responsive materials.

Prof. Cyrille Boyer received his PhD from the University of Montpellier II (2006). After working with Dupont Performance Elastomers, he moved to the University of New South Wales in the centre for advanced macromolecular design. He is now the co-director of Australian Centre for Nanomedicine and member of Centre for Advanced Macromolecular Design. He was awarded the SCOPUS Young Researcher of the Year Award in 2012, one of the six 2015 Prime Minister's Science Prizes (Malcolm McIntosh Prize for Physical Scientist of the year), and the 2016 Le Fevre Memorial Prize awarded by Australian Academy of Science. His research has also been recognized by several international awards, including 2016 ACS Biomacromolecules/ Macromolecules Award, 2016 Journal of Polymer Science Innovation Award, 2018 Polymer International-IUPAC award and 2018 Polymer Chemistry Lectureship. He has co-authored over 250 articles in peer reviewed journals, including Science, Nature Nanotechnology, JACS, ACS Nano, Chemical Sciences, Macromolecules, and Biomacromolecule, which have gathered over 15 000 citations (H-Index = 72). He is also listed as Highly Cited Researcher in Chemistry by Web of Science in 2018.

Announced by the School of Materials Science and Engineering