Dual fire-alarm LBL safeguarding coatings with flame-retardant, EMI shielding and antibacterial properties

Multifunctional safeguarding materials have attracted widespread interests in both environmental and engineering fields. However, most of the protective composite materials are lack of comprehensive protective capability. Here, a facile strategy for making versatile safeguarding coatings based on LBL self-assembly techniques was reported, which was readily prepared with hydrogen bonding and electrostatic interaction. The CNTs@CCS/PANI@PAA coatings showed dual fire-alarm functionality with the resistance change and smoke alarm. Moreover, the safeguarding coatings had significant flame-retardant properties encountering the fire without melt drop or destruction of surface morphology, which dramatically improved the thermal stability and fireproof of the applied coated fabrics. Additionally, the coatings also exhibited remarkable electromagnetic interference (EMI) shielding properties, which was proven to attribute to multiple reflection and interfacial polarization of multilayer interfacial structure. The EMI shielding effectiveness (SE) of the coatings exceeded more than 10 dB in the full X band (8-12 GHz), and the maximal EMI SE of 19.43 dB was achieved. Furthermore, the obtained coatings performed the outstanding antibacterial properties with significantly obvious inhibition zones. In this work, the safeguarding coatings implies promising applications for next-generation versatile materials.