Hanxue Li,Haoliang Huang,Xianguang Yan,Chuanxiang Liu,Liang Li
Dyes are indispensable in the textile industry and are very difficult to degrade due to the presence of two or more benzene rings in their structures. However, the purification of water resources is currently an urgent issue. In this study, a trichlorotriazine-derived calix[4]arene and 1,3,5-tris(4-aminophenyl) benzene were crosslinked to generate a calix[4]arene crosslinked polymer that can serve as a highly efficient adsorbent for separating cationic dyes from water. This research provides evidence for the efficiency of the polymer to adsorb various organic micropollutants in water via batch adsorption experiments. In particular, this polymer exhibited a removal efficiency over 99.6% and 99.4% for methylene blue and toluidine blue within 5 min, respectively. The kinetic results showed that the adsorption process of this polymer for organic dyes could be described with quasi-second-order models, and Langmuir isotherm adsorption models demonstrated that the maximum equilibrium adsorption capacity for methylene blue and toluidine blue was reached to 1806.82 and 2161.32 mg g −1 , respectively. These observations suggest that the adsorption is mainly dependent on the electrostatic interactions, π−π interactions, and hydrogen bonding between the polymer and the organic dyes. Furthermore, the adsorption capacities of the adsorbent were maintained at high levels after five cycles. Its excellent adsorption capability and recyclability make this polymer a promising candidate for potential applications in water purification.
Long-term ingestion or exposure to food contaminated with per- and polyfluoroalkyl substances (PFASs) may cause potential harm to human health. Due to the low contents of PFASs in complex food matrices, it is of great significance to develop adsorbents with excellent properties to enrich PFASs before analysis. Herein, calix[4]arene (CX4) was used as building block to prepare ordered crystalline covalent organic frameworks (COFs). The perfect combination of the host-guest recognition ability of CX4 and the porosity of COFs makes the CX4-COFs selective and high adsorption capacity for linear molecular PFASs (261–1055 mg/g). The adsorption behavior and mechanism were verified by isotherm adsorption experiments and simulation calculations. The CX4-COFs were then used as adsorbents for membrane solid-phase extraction (M-SPE), combined with ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) to determine PFASs in food. The method has low detection limits (0.11–0.28 ng/kg) and good precision (1.3%−9.8%), and has been successfully applied to the simultaneous enrichment and determination of six PFASs in fish, shrimp and shellfish. Satisfactory recoveries (79.9%−118%) were obtained. This study provides a new strategy for preparing CX4-COFs containing macrocyclic molecules with different morphologies and expands the application of COFs as attractive enrichment media for sample pretreatment .
危险品化学品经营许可证（带存储）