題目：Seeing the light: PET-RAFT polymerization and 3D and 4D Printing System

报告人：Cyrille Boyer教授 (University of New South Wales)

时间：12月20号14：00-15：30

地点：实验一楼大会议室

联系人：曹红亮

报告介绍：Reversible addition-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 (λ_max = 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.

报告人介绍：

• Current Positions:

  Full Professor (since January 2017), School of Chemical Engineering, UNSW;

  Australian Research Council - Future Fellow;

  Member of Centre for Advanced Macromolecular Design (CAMD)

  Co-Director (since January 2017), Australian Centre for Nanomedicine; Australia

  Adjunct Professor, Beijing University of Chemical Technology, China

  Adjunct Chair Professor, Soochow University, China

  Adjunct Professor, Fudan University, China

• Number of Publications:

  275+ refereed review and research articles published in peer reviewed journals, including Science, Nature Nanotechnology, JACS, ACS Nano, Chemical Sciences, Langmuir, Chemical Communication, Macromolecules, Molecular Pharmaceuticals, and Biomacromolecules;

  5 international patents (including, 2 provisional patents).

• Number of Citations:

• 16 500+ (according to Google Scholar);

• 50 papers cited 100+ times;

• 25 papers ranked as Highly Cited according to Web of Science;

• H-Index: 75 (H-Index last 5 years: 59) (Google Scholar).