Theme: Development of green Lignin-MWCNTs hybrids for sustainable conductive materials
| Dr. Sofia-Paraskevi Makri holds a bachelor’s degree in physics from the University of Ioannina, an MSc in Nanomedicine from the National and Kapodistrian University of Athens, and a Ph.D. in the field of Biobased Polymers from the Aristotle University of Thessaloniki. Her doctoral research focused on the ultrasound-assisted treatment of lignocellulosic biomass for the production of lignin nanoparticles (LNPs). Since September 2017, she has been working as an R&D Scientist at Creative Nano, specialising in nanotechnology for sustainable applications. Her work involves the development of nanocomposites and hybrid materials using environmentally friendly approaches. She has actively contributed to multiple national and EU-funded R&D projects. Dr. Makri has extensive expertise in nanomaterials characterization and has authored several scientific publications, primarily in the fields of nanotechnology and biobased materials. |
Abstract
| The environmental concerns of electronic industry waste have driven the development of sustainable materials for green electronics. In this study, lignin-based hybrids with multi-walled carbon nanotubes (MWCNTs) were synthesised via an environmentally benign, ultrasonication-based method in aqueous medium, without the use of organic solvents or hazardous chemicals. Two hybrid formulations mainly composed of lignin, a biomass product and MWCNTs at concentrations of 10% and 20% MWCNTs were developed and characterised physiochemically through analytical techniques. Physical interactions between lignin and MWCNTs improved the dispersion and colloidal stability of the resulting hybrids as evaluated by hydrodynamic diameter and zeta potential values through Dynamic Light Scattering (DLS). SEM and TEM micrographs revealed the formation of a lignin matrix embedding a percolated CNT network. Broadband Dielectric Spectroscopy (BDS) was utilised to determine the conductivity of hybrids. Conductivity ranged from 5 to 6 × 10⁻² S/cm for both hybrids, notably close to the conductivity of raw MWCNTs, despite the hybrids containing up to 90 wt% of insulating lignin. Electrochemical study of hybrids showed enhanced electron transfer and overall redox performance as well as increased electroactive surface areas-up to 21 times higher than unmodified electrodes-demonstrating improved electron transfer kinetics. These findings encourage the potential of lignin-MWCNT hybrids as sustainable, conductive fillers in electronic and sensing applications, offering a green alternative to conventional materials. |