| starch/β-CD porous magnetic composite microsphere was prepared by inverse emul sion polymerization method.using soluble starch and β- cyclodextrin(β-CD) as main m aterial, PEG-4000 modified Fe3O4 nanoparticle as magnetic particle, polyvinyl alcohol as Foaming agent, kerosene as oil phase, Span80 and Tween20 as compound emulsifi er, epichlorohydrin(EPI) as crosslinking agent,and characterized the starch/β-CD poro us magnetic composite microsphere by Infrared spectrometer(FI-IR), Laser particle an alyzer, Scanning electron microscopy(SEM),X- ray diffractometer and vibrating sampl e magnetometer(VSM),then discussed the adsorption performance of Cr(Ⅵ) in water with starch/beta cyclodextrin magnetic composite microsphere..First of all, starch/β-CD magnetic microsphere was prepared. studied the effects of reaction temperature, oil and water volume ratio, the stirring speed,dosage of crossli nking agent and reaction time on the microsphere.the results showed that starch/β-CD magnetic microsphere prepared under temperature of 50℃, oil-water ratio of 4:1, EPI dosage of 5 ml, Fe3O4 dosage of 0.5 g, composite emulsifier dosage of 0.9 g(Span80: Tween20 = 2:1), stirring rate of 800 r.min-1and reaction time of 5h was dispersed e venly, it had the characteristic of smoothing,average particle size of 30.763μm, a narro w distribution,Fe3O4 amount of 12.19%, saturation magnetic intensity of 17.87emu/g, and superparamagnetism.Secondly, porous starch/β-CD magnetic composite microsphere was prepared.studied the effects of concentration of PVA, the reaction temperature and stir speed on the microsphere, then taking the adsorption of Cr(Ⅵ) in water as the evaluation index, designed a orthogonal experiment to find best group based on reaction temperature, d osage of EPI, oil-water ratio, stirring speed,amount of PVA,the result showed that poro us starch/β-CD magnetic composite microsphere under reaction temperature of 60 ℃, s tirring speed of 600 r/min, PVA concentration of 1.25%, oil/water volume ratio of 4:1, dosage of EPI of 6ml was dispersed evenly and slightly rough, it had the characteris tics of average particle size of 34.706μm, a narrow distribution span, internal space mesh structure, Fe3O4 contention of 18.91%,and superparamagnetism.Finally, the adsorption performance of Cr(Ⅵ) in water by porous starch/beta cycl odextrin magnetic composite microsphere was discussed. Studied the influence of differ ent adsorption condition on microsphere to treat Cr(Ⅵ) in water,the results displayed that microsphere had the best adsorption performance of Cr(Ⅵ) with56.01 mg.g-1 und er the amount of microsphere of 10 mg, Cr(Ⅵ) initial concentration of 90 mg.L-1,p H of 3-6, adsorption temperature of 20℃, surge time of 90 min in the Water-bathing Co nstant, the adsorption of Cr(Ⅵ) behavior more accorded with the Freundlich adsorptio n model,and the secondary dynamic model was applied to describe the adsorption beh avior of porous starch composite magnetic microsphere. |
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