A multi-scale MXene coating method for preparing washable conductive cotton yarn and fabric

An efficient and simple functional processing method for cotton fabric has been always needed to broaden the application field of cotton fiber. Coating small MXene (S-MXene) and large MXene (L-MXene) on cotton yarn or fabric in turn (SL-MXene) is conducive to the construction of conductive path and improve bonding fastness. SL-MXene coated cotton yarn with fineness of 60 s/2 not only has the best washing resistance, but also has good electrical and mechanical properties. Similarly, the cotton woven fabric coated with SL-MXene (SL-MF), has an electromagnetic shielding efficiency of 42.7 dB with conductivity of 2020 S/m and remains at 33.6 dB or 30.9 dB after washing 50 times or annealing at 250 ℃. Besides, excellent conductivity also enables SL-MF to produce different thermal effects under low voltage excitation, and the temperature can be raised to 122 ℃ under 5 V. This work provides a new design method for cotton fiber functionalization processing, which not only improves the bonding fastness between functional filler and cotton fiber, but also maintains the original flexibility and air permeability of cotton fabric.