Cellulose nanofiber-enhanced MXene screen-printing inks: optimizing printability and coating mechanical properties

The rapid advancement of flexible electronics creates an urgent demand for high-performance printed electronic materials. MXene-based inks have been widely studied and used for screen-printing electronics, while they usually suffer from poor screen-printability and inadequate mechanical properties of the printed coatings. Therefore, we incorporate 2,2,6,6-tetramethylpiperidinooxy oxidized cellulose nanofibers into MXene ink to regulate its rheology and enhance printability on both porous A4 paper and compact polyethylene terephthalate substrates. The introduction of cellulose enables precise control over the rheology and microstructure of the resultant MXene coatings. Critically, the strong interfacial hydrogen bonding and physical entanglement between cellulose and MXene contribute to the substantial enhancements of the mechanical properties and structural stability of the resultant composite coatings, where a remarkable 9.04-fold increase of hardness and a 1.74-fold increase of Young’s modulus are achieved. The interfacial binding strength between the coating and substrate is also well enhanced with the anchoring of cellulose. This work thereby presents a promising strategy for the design and fabrication of flexible screen-printed electronics.