Substrate-Independent Ti3C2Tx MXene Waterborne Paint for Terahertz Absorption and Shielding

With the development of terahertz (THz) technology, there is a booming demand of THz shielding/absorption materials to avoid electromagnetic interference (EMI) or pollution. Paints that can be fast solidified to form a film and stably adherent on arbitrary substrates are especially desired for the shielding/absorption applications. Recently, MXenes with high electron conductivity and hydrophilicity have attracted a great interest for EMI shielding. Here, we demonstrate a copolymer-polyacrylic latex (PAL) based MXene waterborne paint (MWP), which not only has strong THz EMI shielding/absorption efficiency but also can easily adhere onto various substrates that are commonly used in the THz band. The viscosity of MWP can be tuned by adjusting the colloidal and viscous forces, and the cyano group in PAL provides a strong intermolecular polar interaction between MWP and the substrate. As a result, a 38.3-μm-thick MWP on quartz exhibits EMI shielding value of 64.9 dB, and an excellent reflection-loss of 32.8 dB is obtained on MWP coated sponge foam. This substrate-independent MWP provides a simple and efficient way to achieving high-performance THz shielding/absorption.