Fast Visible‐Light 3D Printing of Conductive PEDOT:PSS Hydrogels

• Published in: Macromolecular rapid communications. Vol. 45; no. 1; pp. e2300229 - n/a
• Main Authors: Lopez‐Larrea, Naroa, Gallastegui, Antonela, Lezama, Luis, Criado‐Gonzalez, Miryam, Casado, Nerea, Mecerreyes, David
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2024
• Subjects: 3-D printers; 3D printing; Amines; conducting polymers; Electrical properties; Electron transfer; Hole size; Hydrogels; Hydroxyethyl acrylate; Inks; Light; Monomers; PEDOT:PSS; Photoinitiators; Photopolymerization; Polystyrenes - chemistry; Printing; Printing, Three-Dimensional; Riboflavin; Thiophenes - chemistry; Three dimensional printing; Triethanolamine; Type II photoinitiator system; visible‐light photopolymerization; visible-light photopolymerization; Type II photoinitiator system; hydrogels; conducting polymers; 3D printing; PEDOT:PSS
• ISSN: 1022-1336; 1521-3927; 1521-3927
• DOI: 10.1002/marc.202300229

Functional inks for light‐based 3D printing are actively being searched for being able to exploit all the potentialities of additive manufacturing. Herein, a fast visible‐light photopolymerization process is showed of conductive PEDOT:PSS hydrogels. For this purpose, a new Type II photoinitiator system (PIS) based on riboflavin (Rf), triethanolamine (TEA), and poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is investigated for the visible light photopolymerization of acrylic monomers. PEDOT:PSS has a dual role by accelerating the photoinitiation process and providing conductivity to the obtained hydrogels. Using this PIS, full monomer conversion is achieved in less than 2 min using visible light. First, the PIS mechanism is studied, proposing that electron transfer between the triplet excited state of the dye (3Rf*) and the amine (TEA) is catalyzed by PEDOT:PSS. Second, a series of poly(2‐hydroxyethyl acrylate)/PEDOT:PSS hydrogels with different compositions are obtained by photopolymerization. The presence of PEDOT:PSS negatively influences the swelling properties of hydrogels, but significantly increases its mechanical modulus and electrical properties. The new PIS is also tested for 3D printing in a commercially available Digital Light Processing (DLP) 3D printer (405 nm wavelength), obtaining high resolution and 500 µm hole size conductive scaffolds. Herein, a new Type II photoinitiator system (PIS) is showed based on riboflavin (Rf), triethanolamine (TEA), and PEDOT:PSS conductive polymer for the visible light photopolymerization of acrylic monomers. PEDOT:PSS has a dual role by accelerating the photoinitiation process and providing conductivity to the obtained hydrogels. The new PIS has also been tested for 3D printing, obtaining conducting scaffolds with high resolution.