Fast Visible-Light Photopolymerization in the Presence of Multiwalled Carbon Nanotubes: Toward 3D Printing Conducting Nanocomposites

GALLASTEGUI, ANTONELA; DOMINGUEZ-ALFARO, ANTONIO; LEZAMA, LUIS; ALEGRET, NURIA; PRATO, MAURIZIO; GÓMEZ, MARÍA L.; MECERREYES, DAVID

ACS Macro Letters

ACS Publications

Lugar: Washington; Año: 2022 vol. 11 p. 303 - 309

2161-1653

A new photoinitiator system (PIS) based on Riboflavin (Rf), triethanolamine and multiwalled carbon nanobutes (MWCNTs) is presented for visible light induced photopolymerization of acrylic monomers. Using this PIS, photopolymerization of acrylamide and other acrylic monomers was quantitative in seconds. The intervention mechanism of CNTs in the PIS was studied deeply, proposing a surface interaction of MWCNTs with Rf which favors the radical generation and the initiation step. As a result, poly-acrylamide/MWCNT hydrogel nanocomposites could be obtained with varying amounts of CNTs showing excellent mechanical, thermal and electrical properties. The presence of the MWCNTs influences negatively the swelling properties of the hydrogel, however, significantly improves its mechanical properties (young modulus values) and electric conductivity. The new PIS was tested for 3D printing in a LCD 3D printer. Due to the fast polymerizations, 3D printed objects based on the conductive poly-acrylamide/CNT nanocomposites could be manufactured in minutes.