Preparation Of Aluminum-based MOF Material And Study On Its Adsorption Performance For Bisphenol F Isomer

The resin prepared from bisphenol F,an important chemical raw material,is superior to bisphenol A in both chemical and physical properties.However,bisphenol F has three isomers whose separation is arduous,and the ratio will affect the physical properties of the product.In response to the requirements of green development,it is of great significance to explore an efficient and environmentally friendly separation technology.In this paper,aluminum based metal organic frameworks materials was used as adsorbents to explore the adsorption properties of bisphenol F isomers.The main research is as follows:1.MIL-68(Al)-a and MIL-68(Al)-c were prepared by reflux method,and MIL-68(Al)-b was prepared by hydrothermal method.Futhermore,the prepared materials were characterized and analyzed by characterization methods.The adsorption experiment of bisphenol F isomer showed that the adsorption capacity and selectivity of the MIL-68(Al)-a material to the three mixed bisphenol F are the most excellent.The adsorption capacities of 4,4'-BPF,2,4'-BPF and 2,2'-BPF are 136.25 mg/g,147.33mg/g and 215.18 mg/g respectively.In addition,the selectivities of 4,4'-BPF/2,2'-BPF and 2,4'-BPF/2,2'-BPF are 5.16 and 4.31 respectively.MIL-68(Al)reached equilibrium in the adsorption of bisphenol F isomer at 120 min and still maintained good adsorption effect after five cycles.Moreover,the ionic strength had no effect on the adsorption of MIL-68(Al).Futhermore,the adsorption rate was jointly controlled by internal diffusion and external diffusion,which conformed to the quasi-second-order kinetic model and Langmuir adsorption isotherm model.The data fitting results of Temkin model and Dubinin-Radushkevich model demonstrated that the adsorption process of MIL-68(Al)for bisphenol F belongs to physical adsorption process,and the thermodynamic fitting results indicated that adsorption is an exothermic,spontaneous and entropy reduction process.2.NH2-MIL-68(Al),Br-MIL-68(Al),Br₂-MIL-68(Al),HO-MIL-68(Al),(HO)₂-MIL-68(Al),Na SO₃-MIL-68(Al),NO₂-MIL-68(Al)and biphenyl-MIL-68(Al)and other functional materials were prepared by reflux method,and then the functionalized materials was detected and analyzed via characterization methods.The adsorption experiments on bisphenol F isomers showed that Br-MIL-68(Al),HO-MIL-68(Al),(HO)₂-MIL-68(Al),NO₂-MIL-68(Al)and biphenyl-MIL-68(Al)had good adsorption properties for them.And Br-MIL-68(Al)has the advantages of large adsorption capacity and effective selectivity whose adsorption capacities of 4,4'-BPF,2,4'-BPF and 2,2'-BPF are 79.33 mg/g,91.60 mg/g and 198.40 mg/g respectively.Moreover,the selectivities of 4,4'-BPF/2,2'-BPF and 4,4'-BPF/2,2'-BPF are 7.99 and 5.81respectively.Besides,Br-MIL-68(Al)reached equilibrium of adsorption at 90 min and still maintained good adsorption effect after five cycles.Moreover,the ionic strength had no effect on the adsorption of Br-MIL-68(Al).Futhermore,the adsorption rate is controlled by both internal and external diffusion,which conformed to the quasi-second-order kinetic model and Langmuir adsorption isotherm model.The Temkin model fitting results indicated that the adsorption process of bisphenol F by Br-MIL-68(Al)is a physical adsorption process,and the thermodynamic fitting results turned out that adsorption is an exothermic,spontaneous and entropy reduction process.