微乳液原位制备磁性壳聚糖纳米粒子及其对染料的吸附性能

In-Situ Preparation of Magnetic Chitosan Nanoparticles in Microemulsion System and Their Adsorption Properties for Dyes

利用环己烷/正己醇、壳聚糖、Fe2+/Fe3+盐和Triton X-100组成的W/O微乳体系中加NaOH溶液沉淀剂,原位制备磁性壳聚糖纳米粒子,并经乙二胺改性(EMCN),用于吸附酸性橙12(AO12)和酸性橙10(AO10)。利用透射电镜、X-射线衍射、红外等对产物进行了表征。结果表明,EMCN分散良好,粒径15 nm^40 nm,饱和磁化强度25.6 emu/g。AO12和AO10最佳pH值分别为4.0和3.0;吸附速率很快,平衡时间40 min^60 min。吸附平衡用Langmuir模型拟合最好,饱和吸附容量分别为AO12 2.81 mmol/g,AO10 1.82 mmol/g。由D-R模型计算E值(14.95 kJ/mol^18.54 kJ/mol)表明以化学吸附为主。EMCN可用NH4OH/NH4Cl(pH10.0)溶液再生。

The magnetic chitosan nanoparticles（MCN） were in-situ prepared by adding the NaOH solution precipitant into a W/O microemulsion system containing cyclehexane/n-hexanol,chitosan,Fe2＋/Fe3＋ salts and Triton X-100.The MCN were then modified with ethylenediamine（EMCN） and used for the adsorption of Acid Orange 12（AO12） and Acid Orange 10（AO10）.The adsorbents were characterized by TEM,XRD and FT-IR.The results show that EMCN are monodispersed,and have a particle size of 15 nm～40 nm and a saturation magnetization of 25.6 emu/g.The maximum adsorption occurred at pH 4.0 for AO12 and pH 3.0 for AO10,respectively.The adsorption was very quick with the equilibrium time of 40 min～60 min.The equilibrium data fitted well with Langmuir isotherm,and the saturation adsorption capacity was 2.81 mmol/g for AO12 and 1.82 mmol/g for AO10,respectively.The E values（14.95 kJ/mol～18.54 kJ/mol） calculated form D-R isotherm indicated that the chemisorption was predominant on the adsorption.The EMCN could be regenerated using NH4OH/NH4Cl solution（pH 10.0） as elution.