Facile fabrication of hierarchically porous melamine foam@COF composite for sample treatment of non-targeted food safety analysis and oil/water separation

The design of high-efficiency adsorbents for facile and rapid sample treatment of non-targeted food safety analysis and oil/water separation is challenging but of great significance to food and environment safety. To overcome the poor processability of covalent organic frameworks (COFs) powders and improve their application performances, a heteropore COF-based monolithic material (MF@COF composite) was prepared by selecting melamine foam (MF) as a supporter, whose surface has abundant amino groups, which makes the direct in-situ growth of COF and thus the one-pot synthesis of MF@COF possible. As-prepared MF@COF integrates the advantages of MF and COF, giving attractive properties such as highly hierarchical pores, strong hydrophobicity, ultralight weight, robust stability, good mechanical elasticity, and processability. These, together with the easy operation feature of monolithic material, make MF@COF work well for the sample treatment of non-targeted food safety analysis and oil/water separation. Nearly complete matrices removal from 6 kinds of representative fat-rich foods was achieved in 30 s, accompanied by the “full recovery” of 323 chemical hazards. The good oil/water separation capability was demonstrated by selective removal of light oil and heavy oil from oil/water systems, demulsification of oil/water emulsion, as well as 35–140 times weight increase after organic solvent or oil absorption.