Carrageenan based printable magnetic nanocomposites for actuator applications
Vera M. Macedo, Nélson Pereira, Carmen R. Tubío, P. Martins, Carlos M. Costa, S. Lanceros‐Méndez
Abstract
The digitalization of the society in the context of the Internet of Things (IoT) demands a new generation of sustainable materials and processes to reduce the environmental impact of technological advances. This work reports on sustainable multifunctional nanocomposites based on carrageenan and magnetic cobalt ferrite (CoFe2O4-CFO) nanoparticles, processed by direct-ink-writing and on their applicability as magnetic actuators. The nanocomposites exhibit a compact morphology with CFO nanoparticles well distributed within the polymer matrix. The incorporation of CFO nanoparticles significantly improves the thermal and mechanical properties of the polymer: the onset degradation temperature increases 30 °C and the Young's modulus increases from 1 MPa in the pristine polymer to 17 MPa for the composite with 5 wt% CFO content. CFO magnetic nanoparticles are also responsible for increasing the dielectric constant of carrageenan from ≈1000 up to ≈9000 (10 wt% CFO composite), and for the magnetic properties, with a maximum magnetization of ≈16 emu.g−1 and coercive field of ≈3.4 kOe in the 30 wt% CFO composite. A magnetic actuator has been developed with excellent maximum displacement.