Preparation Of Polymers Of Intrinsic Microporosity Composite Materials For Dye Adsorption

Adsorption technology has become a promising purification method due to its low cost,high efficiency,and environmental friendliness.At present,adsorption technology has been widely used to purify wastewater containing various of pollutants such as heavy metals,dyes,spilled oil,aromatics,and pesticides.Although adsorption has made great progress,conventional adsorbents have several disadvantages such as limited porosity,unadjustable structure,slow adsorption kinetics,limited adsorption selectivity,and poor regeneration cyclability.Aming at this problem,polymers of intrinsic microporosity(PIMs)were mixed with functional materials to obtain a composite adsorbent with high efficiency,high selectivity,and easy separation character.The main contents of this research are as follows:(1)Preparation of magnetic functionalized hydrolysis PIM-1 for dye adsorptionHPIM/Fe₃O₄ composite adsorbent was prepared by the phase inversion and hydrolysis process.Thereinto,the carboxyl-modified PIM-1 has high adsorption performance for cationic dyes and the loaded Fe₃O₄ could provide the compound excellent magnetic separation ability.The successful preparation of HPIM/Fe₃O₄were confirmed by various characterization methods.The influence of various factors on the adsorption process were investigated by using methylene blue(MB)as the target dye,and the process was simulated by adsorption kinetics,isotherms and thermodynamics to investigate the intrinsic adsorption mechanism.The results showed that p H,contact time,initial MB concentration,temperature,and number of cycles all affected the adsorption process.HPIM/Fe₃O₄ showed high adsorption capacity for MB dye,and the maximum adsorption capacity obtained by fitting the Langmuir model was up to 413.2 mg g^-1.After 10 adsorption/desorption cycles,the adsorption capacity of adsorbent only showed slight decrease.(2)Preparation of amidoxime modified PIM-1/alginate composite hydrogel beads for dye adsorptionPIM-1 was firstly modified into the amidoxime PIM-1(AOPIM-1)by hydroxylamine,then the amidoxime PIM-1/alginate(AOPIM/Alg)composite hydrogel beads were prapred by ion gel technology.A variety of characterization methods(¹H NMR,FTIR,TGA,SEM,and N₂ adsorption measurement)were used to verify the successful synthesis of AOPIM/Alg hydrogel beads.The malachite green(MG)was used to study the influence of composite ratio,contact time,intial MG concentration,temperature,and number of cycles on the adsorption performance of composite beads.Adsorption kinetics,isotherms and thermodynamics were studied to explore the internal mechanism of AOPIM/Alg beads about the adsorption process.In addition,the adsorption characteristics of AOPIM/Alg beads for mixed dye solutions were also studied.After 10 adsorption/desorption cycles,the adsorption capacity of the composite beads can be maintained more than 90%of the initial adsorption capacity.