Three-Dimensional Polymer Nanofiber Structures for Liquid Contamination Adsorption
Yunjie Liu, Yanting Li, Yonglei Liu, Pengjian Gong, Yanhua Niu, Chul B. Park, Guangxian Li
Abstract
Green amphiphilic decontamination materials with high-performance, ultrafast, and highly efficient liquid contamination adsorption are of great significance to environmental protection. In this work, an ethylene-vinyl alcohol copolymer with both hydrophilic and hydrophobic chain fragments was selected as the matrix (amphiphilic adsorption), a topological grafting structure was designed for chain entanglement (to enhance fiber integrity), and then the aggregate structure was controlled with a soft dispersed phase (to facilitate fiber formation). Finally, environmental-friendly supercritical CO2 foaming is used to obtain the three-dimensional (3D) polymer nanofiber structures (to increase fiber-structure porosity) for liquid contamination adsorption. The strategy takes full advantage of the synergistic effect from the multi-scale structure, including the random copolymer structure (repeating unit scale in the molecular chain), topological structure (molecular chain scale), microphase separation structure (aggregate scale), and nanofiber structure (porous scale). The obtained adsorption amphiphilic material adsorbed liquid contamination with a high efficiency of 64.78 g/g and a large adsorption rate of 1.14 g/g·s–1 (kinetic constant) for carbon tetrachloride, attributing to its unique 3D polymer nanofiber structure with a large specific surface area and a large amount of porous space to adhere and to be filled by liquid contamination, respectively. This work provided a strategy for the green preparation of environment-friendly and high-performance decontamination materials.