庚醛改性壳聚糖的制备及其对酚类化合物的吸附性能

Preparation of N-Alkyl Chitosan and Its Adsorption of 2,4-Dichlorophenol

在相转移催化剂存在下由庚醛与壳聚糖反应生成Schiff′s碱,再用NaBH4还原制备了N-烷基化壳聚糖衍生物,改性壳聚糖(CTS)产物的结构用FTIR和XRD进行了表征,研究了它对2,4-二氯酚的吸附性能。考察了吸附时间、溶液pH值、2,4-二氯酚浓度和改性剂用量等因素对吸附的影响。结果表明,改性CTS具有较好的抗酸碱性能;溶液的pH值对吸附的影响较大,在pH=6.0,吸附2 h时对2,4-二氯酚的吸附量最大,酚浓度对吸附的影响符合Freundlich吸附等温方程;改性壳聚糖对2,4-二氯酚的吸附性能明显优于未改性的CTS,对质量浓度为0.6 g/L的2,4-二氯酚溶液的吸附量分别为70.0和7.7 mg/g。

A N-alkyl chitosan derivative was synthesized by reducing Schiff＇ base formed from the reaction of n-Heptaldehyde and chitosan via phase transfer catalysis. The modified chitosan was characterized by FFIR and XRD. The chitosan derivative was applied to adsorbing 2,4-dichlorophenol. The effects of adsorption conditions, such as time, pH, the concentration of 2,4-dichlorophenol, and the amount of the modified chitosan on the adsorption quantity of 2,4-dichlorophenol were studied. The N-alkyl chitosan exhibited good acid resistance. The solution pH was the main factor affectomg the adsorption. At pH 6. 0, the adsorption of 2,4-dichlorophenol reached the maximum in 2 h. The relationship between the concentration of 2,4-dichlorophenol and the adsorption quantity was fitted well to Freundlich equation. N-alky[ chitosan showed better adsorption capability than chitosan. Adsorption capacity of the modified chitosan and chitosan for 2,4-dichlorophenol of 0.6 g/L concentration was 70. 0 mg/g and 7. 7 mg/g, respectively.