Study On Preparation Of Porous Polymer Matericals And Their Adsorption Properties

With the rapid development of industries,the dye wastewater has become one of the main sources of water pollution.At present,among numerous treatments of dye wastewater,the adsorption method is one of the commonly used treatment methods because of its advantages such as large amount of waste water treatments and simple operations.The key of the adsorption method is the adsorbent materials.According to many reports,the adsorbent obtains better adsorption properties with a large specific surface area and active functional groups.In recent years,porous materials have received extensive attention due to their inherent advantages such as a large specific surface area.In this work,several porous materials with different properties were prepared and their adsorption properties of sunset yellow FCF(SY)were systematically studied,which mainly included the following aspects:(1)Ionic liquid modified cross-linked porous chitosan(P[AMIM]Cl-g-CCB)was prepared by the modification of cross-linked porous chitosan(CCB)with 1-propenyl-3-methylimidazolium chloride salt([AMIM]Cl),using ammonium persulfate as initiator,to remove sunset yellow FCF(SY).The products was characterized by Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),thermogravimetric analysis(TGA)and nitrogen adsorption-desorption measurment.And the effects of solution pH,the amount of adsorbent and adsorption time on the adsorption performance were investigated.The results showed that better experimental conditions for removal of SY were solution pH 7.0,4 mg of adsorbents and 60 min of adsorption time.The adsorption isotherm can be well fitted by Langmuir model.The adsorption process can be described by pseudo-second-order kinetic equation.Adsorption thermodynamics showed that the adsorption process was a spontaneous,exothermic and entropy decrease process.(2)Polydopamine-coated silica gel was modified by diethylenetriamine(SG@DETA/PDA)as an adsorption material for SY adsorption from aqueous solution,by using silica gel and diethylenetriamine(DETA)as the substrate and the modifier,respectively.The prepared adsorbent materials were characterized by FTIR,SEM,TGA and nitrogen adsorption-desorption tests.The effects of solution pH,the amount of adsorbent,adsorption time and the concentration of dye on the adsorption of sunset yellow FCF were investigated.The adsorption isotherm for sunset yellow FCF adsorption on the adsorbent can be described by Langmuir equation,and the results showed that the calculated adsorption capacity was 174.22 mg/g and the adsorption was favorable.The adsorption kinetics data can be fitted with pesudo-second-order kinetics equation,and adsorption thermodynamics shows the SY adsorption onto SG@DETA/PDA was a spontaneous and entropy increase process.(3)A high specific surface area amine-modified PIM-1(NH2-PIM-1)was synthesized as an adsorbent to remove sunset yellow FCF(SY)from aqueous solution,used tetrahydrofuran borane complex as a reductant to reduce nitriles to amines in the polymer of intrinsic microporosity(PIM-1).The morphology and structure of NH2-PIM-1 were characterized by FTIR,SEM,TGA,13C solid-state nuclear magnetic resonance(SSNMR)and nitrogen adsorption-desorption tests.The effects of solution pH,the amount of adsorbent and adsorption time on the removal of SY were systematically investigated.The results showed that the maximum adsorption capacity of NH2-PIM-1 was 348.16 mg/g.The adsorption kinetics and adsorption isotherms can be well fitted by pseudo-second-order kinetic equation and Langmuir model,respectively.Thermodynamics analysis shows that the adsorption process was a spontaneous physisorption process.