Preparation And Adsorption Properties Of Metal-Organic Framework Composites

Metal-Organic Frameworks(MOFs)have been extensively studied in the trapping of hazardous substances due to their large specific surface area,high porosity and good chemical stability.In this paper,based on MOFs material,MOF@CF and UiO-66-OH@TGIC composite materials were prepared by combining with cellulose and TGIC respectively,intending to expand the application of MOFs material in the field of adsorption.The specific contents are as follows:(1)In order to reduce the nicotine content in cigarette,six low-toxicity MOFs(UiO-66,UiO-66-NH2,UiO-66-OH,HKUST-1,ZIF-8 and MOF-74)were mixed into naturally degradable bamboo pulp cellulose fibers to prepare a series of adsorption materials abbreviated as MOF@CF.The nicotine adsorption experiment was carried out in a self-designed experimental device,and the experimental results were analyzed and characterized.The results showed that UiO-66@CF had the best mechanical properties and the best nicotine adsorption rate,and the removal efficiency was up to 90%(the relative standard deviation of the experiment was less than 8.80%),which may be caused by large pore size,open metal sites and high load in cellulose fibers of UiO-66.In addition,UiO66@CF still had an 85%nicotine removal rate after three adsorption cycles.Through the DFT calculation,it was found that UiO-66 was closest to the energy difference between HOMO and LUMO in nicotine,further proving that the material had strong nicotine adsorption capacity.Due to good flexibility,recyclability and absorbability,the prepared hybrid UiO-66@CF has a broad application prospect in the adsorption of nicotine in cigarette.(2)In order to solve the defect of unstable dye removal rate of UiO-66-OH under different pH conditions,we combined UiO-66-OH with TGIC by a simple mechanical abrasive method.UiO-66-OH was combined with TGIC by a simple mechanical grinding method,and UiO-66-OH@TGIC was prepared by covalent bonding between the terpolymer oxygen-containing ring on TGIC and the hydroxyl group and unmatched carboxyl group on UiO-66-OH.The thermogravimetric results showed that the thermal stability of UiO-66-OH was enhanced by the curing reaction.In addition,the adsorption capacity of the composite to four different dyes in different pH environments was studied.The experimental results showed that the composite had stable adsorption capacity of dye under acid-base environment,and the UiO-66-OH@TGIC still had a high removal rate of coomassie brilliant blue after five cycles,which further improved the practical application of MOFs in the field of sewage treatment.