| Polyurethane foam(PUF)as a kind of porous material has been widely used.Phenol and its derivatives in industrial waste are harmful to the environment due to the high toxicity.Owing to special hollow structure of ?-cyclodextrin(?-CD)and carboxymethyl-?-cyclodextrin(CM?-CD),forming stable clathrates with phenol,the phenol in wastewater can be removed.In addition,according to the principle of interaction between protein and plant polyphenols,adsorbent material loaded protein can be employed to remove excess plant polyphenols in drinks and herbs.In this paper,the inclusion formation of ?-CD with phenol/naphthol was studied,using phenolphthalein and methyl orange as probe molecules.PUF was employed as substrate and films were boiled in HCl to liberate the maximum number of free amino groups,as a result,aminated PUF was obtained and was used as general material for the following reaction.?-CD was coupled to the surface of aminated PUF under the conditions of high temperature and reflux.CM?-CD was coupled to the surface of aminated PUF by using strategies of diazo and UV irradiation,as a result,adsorbent materials for phenol were obtained.Gelatin was coupled to the surface of aminated PUF by using the methods of diazo and UV irradiation,achiving adsorbent material for plant polyphenols.The effect of modification conditions and adsorption conditions on adsorption properties were investigated.Adsorption equilibrium,kinetics and thermodynamics were also researched.Finally,the material regeneration and recycling adsorption performance were preliminarily explored.The results show that the inclusion ratio between ?-CD and phenol/naphthol was 1:1.Inclusion went on better under acidic or neutral condition.In comparison of inclusion constant,phenolphthalein was more suitable as probe molecule of ?-CD with phenol.Aminated PUF with 0.7870 mmol g-1 amino content was obtained under the optimal condition.The material coupled ?-CD with ?-CD content was N1=799.69 mg g-1 and N2=810.42mg g-1 measured by phenolphthalein discoloration and methyl orange discoloration,respectively.Material coupled CM?-CD with CM?-CD content was 166.72 mg·g-1.The maximum adsorption capacity for phenol of two modified adsorbent were 144.58mg·g-1 and 180.14 mg·g-1 respectively,associated with 1100 mg·L-1 of phenol concentration,4h of adsorption time,30 ? of adsorption temperature,as well as the values of pH 7.2 of phenol solution.Adsorption equilibrium can well be described by Tempkin model and Freundlich model,respectively.The adsorption process was an exothermic reaction and can be well fitted by second-order model.Material coupled ?-CD still has a good adsorption performance when it was desorbed 4 times and material coupled CM?-CD still has a good adsorption performance when it was desorbed 2 times.Material coupled gelatin with gelatin content calculated with amino acids was 44.59mg·g-1 under the optimum condition.The maximum adsorption capacity for tannic acid was 49.05mg·g-1 under the conditions of 200mg·L-1 of tannic acid concentration,4h of adsorption time,40? of adsorption temperature.Langmuir model can be well describe the adsorption equilibrium,indicating monolayer adsorption of modified material for tannic acid.The results of thermodynamics and kinetics of adsorption imply that the adsorption process was an exothermic reaction,and can be explaned by pseudo second-order model.Adsorbent still has a high adsorption performance for tannic acid when it was desorbed 4 times.Hydrophilic,SEM,ATR-FTIR and XPS were employed to analyze the surface properties,composition and structure of adsorbents.The results confirm that the materials coupled ?-CD or CM?-CD or gelatin molecules exhibit good adsorption capicity for phenol or plant polyphenols. |
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