| To reduce and suppress various hazards caused by electromagnetic interference（EMI）and radiation,EMI shielding technology emerged.Among various forms of shielding materials,EMI shielding textiles have received wide attention in protecting the human body and sensitive electronic devices from electromagnetic radiation for their light weight,extraordinary flexibility and superior adaptability.Two-dimensional transition metal carbide（MXene）has excellent metallic conductivity and abundant surface functional groups,making it an ideal component for preparing EMI shielding textiles.Moreover,the introduction of MXene can endow the textiles with multifunctional performances,such as gas sensing,photo-thermal conversion,and joule heating.However,due to the wide size distribution and easy agglomeration of MXene nanosheets,it is difficult to assemble them into an interconnected conduction network.To address this problem,one-dimensional conductive nanomaterials:polyaniline（PANI）nanowires or carbon nanotubes（CNTs）are introduced into MXene coating by a layer-by-layer assembly method.We design the functional PANI/MXene/cotton fabrics with ammonia sensing and tunable EMI shielding performances,and the multifunctional MXene/CNT textiles integrating electromagnetic protection,strain sensing,and thermal management functions,providing novel ideas for the preparation and application of EMI shielding textiles.The main research contents and results are given as follows:（1）Functional PANI/MXene/cotton fabrics with tunable electromagnetic interference shielding performances:PANI with adjustable conductivity is selected as the responsive material,and functional PANI/MXene/cotton fabrics（PMCF）are prepared by spraying MXene and PANI layer by layer on cotton fabric substrates.The synergistic effect of MXene and PANI on ammonia endows the PMCF with superior ammonia sensing performances of 19.65%response to 200 ppm ammonia,and outstanding selectivity and repeatability.The excellent conductivity of the PMCF and the abundant interfaces in the conductive coating facilitate the reflection and absorption of electromagnetic waves,providing the PMCF with a high EMI shielding effectiveness of 54 d B.Most importantly,the PMCF exhibits distinctive acid/alkali-responsive performances,which can adaptively adjust its EMI shielding effectiveness in response to the variations of acid or alkali environments,achieving a switch between the efficient strong shielding of 24 d B and the inefficient weak shielding of 15 d B.（2）Preparation and performances of multifunctional MXene/CNT electromagnetic interference shielding textiles:Multifunctional MXene/CNT textiles（MCTex）are prepared by spraying MXene and CNTs layer by layer on a stretchable polyester-spandex four-sided stretch textile.The excellent EMI shielding performances of the MCTex originate from the conductive network constructed by the layer-by-layer assembly of MXene and CNTs.The EMI shielding effectiveness of the MCTex is up to 43.9 d B when the concentrations of MXene and CNTs are 5 and 3 mg m L-1,respectively.It is worth noting that the sensitivity of tensile strain along the wale direction is higher than that course direction due to the special weft structure of the MCTex.The favorable strain sensing performances of MCTex enable it to detect human motion and physiological signals.Moreover,the MCTex exhibits dual-energy-driven heating performances with steady temperatures of103 and 63.7°C at a voltage of 3 V and an optical power density of 250 m W cm-2,respectively. |
