The promise of carbon nano-onions for thermoplastic and biodegradable thermoplastic nanocomposites—status quo and future vision

As one of most fascinating form of carbonaceous nanoentities, presently, carbon nano-onions and derived nanomaterials attained intense scientific curiosities. Accordingly, this review bids readers with an updated account on recent progresses in the arenas of thermoplastic polymers/carbon nano-onions hybrids. Carbon nano-onions and modified forms have been reinforced in a variety of thermoplastics to form advanced polyethylene/carbon nano-onions, poly (methyl methacrylate)/carbonaceous nano-onions, polyacrylonitrile/carbonaceous nano-onions, polyamide/carbonaceous nano-onions, polystyrene/carbonaceous nano-onions, and other multifunctional nanocomposites. Similarly, with biodegradable thermoplastics, poly (vinyl alcohol)/carbon nano-onions, poly (lactic acid)/carbonaceous nano-onions, chitosan/carbonaceous nano-onions, etc., have been designed. The ensuing nanocomposites had noticeable microstructural features, electrical conductivity, mechanical robustness, thermal stability, ecological/sustainability, and other valuable physical properties. Depending upon explicit technical features, carbon nano-onions based nanomaterials revealed applications in a number of industrial sectors. Currently, thermoplastic polymers/carbon nano-onions nanomaterials seemed to be promising for electromagnetic interference shielding, sustainable water purification, biomedical (drug delivery, bioimplants), and scientific interests continuously growing in these areas. Along with the design varieties, synthetic routes, compatibility aspects, etc., of carbon nano-onions filled nanocomposites, the underlying challenges towards their practical utilization were also concisely detailed out.