Functional Polyaniline/MXene/Cotton Fabrics with Acid/Alkali-Responsive and Tunable Electromagnetic Interference Shielding Performances.

Although two-dimensional transition-metal carbides (MXenes) and intrinsic conductive polymers have been combined to produce functional electromagnetic interference (EMI) shielding composites, acid/alkali-responsive EMI shielding textiles have not been reported. Herein, electrically conductive polyaniline (PANI)/MXene/cotton fabrics (PMCFs) are fabricated by an efficient vacuum filtration-assisted spray-coating method for acid/alkali-responsive and tunable EMI shielding applications on the basis of the high electrical conductivity of MXene sheets and the acid/alkali doping/de-doping feature of PANI nanowires. The as-prepared PMCF exhibits a sensitive ammonia response of 19.6% at an ammonia concentration of 200 ppm. The high EMI shielding efficiency of ∼54 dB is achieved by optimizing the decorated structure of the PANI/MXene coating on the cotton fabrics. More importantly, the PMCF can act adaptively as a "switch" for EMI shielding between the efficient strong shielding of 24 dB and the inefficient weak shielding of 15 dB driven by the stimulation of hydrogen chloride and ammonia vapors. This multifunctional fabric would possess promising applications for intelligent garments, flexible electronic sensors, and smart electromagnetic wave response in special environments.