A novel approach to prepare polyaniline/Polypyrrole@Cu-BTC/NH2-MIL-101(Fe) MOFs for electromagnetic wave absorption

Abstract

In this study, the Cu-BTC and NH2-MIL 101 (Fe)@polypyrrole and polyaniline core–shell particles were prepared by in situ polymerization of pyrrole and aniline monomers on the surface of Cu-BTC and NH2-MIL 101 (Fe) for electromagnetic wave absorption applications. Firstly, the Cu-BTC (1,3,5 benzenetricarboxylic acid, BTC) and NH2-chromium (III) terephthalate (MIL-101) were synthesized by solvothermal method. Secondly, the surface of Cu-BTC and NH2-MIL 101 (Fe) mixtures were coated with polypyrrole (PPy) and polyaniline (PANI) by a polymerization of aniline (An) and pyrrole (Py) monomers and denoted as PP@Fe/Cu. For comparative studies, the aniline (An) and pyrrole (Py) monomers were polymerized in the same condition on the surface of NH2-MIL-101 (Fe) powder without the presence of Cu-BTC and the final powder was denoted as PP@Fe. The morphologies, phase structures and magnetic properties of products were characterized by scanning electron microscope (SEM), X-ray diffractometer (XRD), and vibrating sample magnetometer (VSM) machines. The complex permeability and permittivity values of PP@Fe and PP@Cu/Fe were determined in the range of Ku band (12.4–18 GHz). The electromagnetic wave absorption performances were evaluated using obtained permittivity and permeability values. It was observed that PP@Fe and PP@Cu/Fe composites displayed excellent microwave absorption performances. The existence of Cu-BTC into NH2-MIL 101 (Fe) further enhanced the minimum reflection loss from −60 dB to −80 dB.