Conjugated Polymer Nanoparticles as Visible Light Panchromatic Photoinitiators for 3D Printing of Acrylic Hydrogels

CAGNETTA, GONZALO E.; GALLASTEGUI, ANTONELA; MARTÍNEZ, SOL R.; MANTIONE, DANIELE; CRIADO-GONZALEZ, MIRYAM; REGATO-HERBELLA, MARIA; LEZAMA, LUIS; PALACIOS, RODRIGO E.; GÓMEZ, M. LORENA; MECERREYES, DAVID; CHESTA, CARLOS A.

MACROMOLECULES

AMER CHEMICAL SOC

Lugar: Washington; Año: 2023

0024-9297

Conjugated polymers (CPs) have been reported to generate reactive oxygen species (ROS), hydrogen and hydrogen peroxide through photoinduced charge transfer processes involving water or oxygen. In this work, this ability to generate radicals is investigated here as photoinitiator systems (PIS) for the polymerization of acrylic monomers in aqueous media. For this purpose, nanoparticles (CPNs) have been synthesized by nanoprecipitation from different polymers covering the visible light spectrum. The capacity of these CPNs to act as photoinitiators for water-soluble acrylic monomers was studied. All CPNs initiate photopolymerization effectively achieving high conversions (60-99%) and their wide light absorption properties reveal a panchromatic behaviour initiating photopolymerization employing both blue, green and red LEDs as excitation sources. Photopolymerized hydrogels were characterized by rheology showing high swelling degree (water uptake in the range 900-1600 %) and major gel fraction (in the range 70-97 %). The CPNs are homogeneously distributed in the hydrogel matrix while keeping their optical properties as observed by confocal microscopy. They keep their ability to generate radicals within the hydrogels as shown by its bacteria photodynamic inactivation ability. Finally, the most efficient CPN PIS were successfully employed to print a 3D object by digital light processing with high resolutions (100 μm).