Technological challenges and progress in nanomaterials plasma surface modification – A review

Nanoscale particulate materials draw great interest in an increasing number of applications, such as electronics,energy storage, automotive, health or environment. In particular, the addition of nanofillers in a polymer matrixcan significantly improve the thermal, mechanical, electrical, optical, and biological or corrosion protectionproperties of a nanocomposite, provided that thefillers exist as discrete entities and strongly adhere to thematrix. Nanocomposite synthesis generates major technological challenges, due to the natural tendency of na-nomaterials to agglomerate and to their poor compatibility with polymeric materials. The main approach totackle these issues consists in modifying thefillers surface to enhance their affinity with the matrix and producerepulsive interactions between the particles. In this paper, after a brief review of the conventional“wet”methodsused to modify the surface of nanomaterials, we highlight the numerous technical, environmental and economicadvantages provided by dry and versatile plasma treatments. Then, we present the different plasma reactorconfigurations designed so far, for powders surface functionalization. In particular, we spotlight the advantagesand drawbacks of each system regarding particle mixing, powder yields and up-scaling possibilities. Finally, weintroduce the main characterization tools generally used to analyze modified nanopowders. In this last part, weunderline the main results and achievements obtained up to now in terms of treatment uniformity, functiona-lization degree, dispersibility/stability enhancement and improvement of nanocomposite performances