黄腐酸类离子印迹材料的制备及其吸附研究

发布时间：2018-08-20 12:27

【摘要】：离子印迹材料是一种新型的有机高分子吸附材料,对重金属离子拥有特异性识别吸附能力,对环境中重金属处理实现了单一金属离子的特异性吸附。以黄腐酸为基本原料,经过一系列试验处理,合成了对Cd~(2+)具有专一吸附能力的离子印迹聚合物,并对产物结构和性能进行分析。1)以黄腐酸为原料,环氧氯丙烷为改性剂,碱性条件下合成带有小分子基团CH_2OCHCH~(2-)的改性黄腐酸。通过优化工艺条件,得出黄腐酸在改性过程中的最佳原料投入比以及较好的反应时间和反应温度。优化反应条件后,产物中环氧基团的最大含量为0.88 mol/100 g(优化工艺条件是:投料质量比、反应时间、反应温度,此时最大环氧基团含量为0.88 mol/100 g)。采用红外光谱、紫外-可见分光光度计和扫描电镜对产物结构和表面形貌进行了表征。2)以改性黄腐酸为功能单体,乙二胺作交联剂,通过反相悬浮聚合法合成Cd~(2+)离子印迹聚合物(MFA-IIP),通过红外光谱、扫描电镜、热重分析表征产物的结构特征,并对产物的吸附能力进行了研究。通过考察合成工艺发现,当改性黄腐酸用量是0.5000 g,Cd~(2+)离子(3.0 g/L)溶液加入量为30 mL,乙二胺投入量为20 mL,反应时间为12 h,反应温度为60℃时,所得产物对Cd~(2+)离子的吸附效果最好。合成的离子印迹聚合物结构稳定,循环使用3~4次后,自身结构和去除能力无明显变化。3)以Fe_3O_4/SiO_2为磁核,改性黄腐酸为功能单体,KH-550为交联剂,合成了磁性Cd~(2+)离子印迹聚合物(MFA-M-IIP)。表征发现,聚合物制备过程中保留了Fe_3O_4/SiO_2良好的顺磁性,有利于产物的简单快速分离。吸附研究发现,最优吸附条件时,磁性Cd~(2+)离子印迹聚合物对模板离子的最大吸附量为2.48 mg/g,去除率达到99.37%。竞争吸附研究证明,Cd~(2+)/Pb~(2+)、Cd~(2+)/Cr3+的选择性系数分别为79.68和136.82。聚合物对Cd~(2+)离子的吸附行为符合准二级动力学模型和Langmuir等温吸附模型。
[Abstract]:Ion-imprinted material is a new kind of organic polymer adsorption material. It has the ability to recognize and adsorb heavy metal ions, and realize the specific adsorption of single metal ions to heavy metals in the environment. Using fulvic acid as the basic raw material, the ionic imprinted polymer with specific adsorption capacity for Cd2 was synthesized through a series of experimental treatments. The structure and properties of the product were analyzed. 1) with fulvic acid as the raw material and epichlorohydrin as the modifier, A modified fulvic acid with small molecular group CH2OCHCH2- was synthesized under alkaline condition. The optimum raw material input ratio, reaction time and reaction temperature of fulvic acid in the modification process were obtained by optimizing the process conditions. When the reaction conditions were optimized, the maximum content of epoxy group in the product was 0.88 mol/100 g. The optimum conditions were as follows: feed mass ratio, reaction time, reaction temperature, and the maximum epoxy group content was 0.88 mol/100 g). The structure and surface morphology of the product were characterized by infrared spectroscopy, UV-Vis spectrophotometer and scanning electron microscope (SEM). The modified fulvic acid was used as functional monomer and ethylenediamine as crosslinking agent. Cd2 ion-imprinted polymer (MFA-IIP) was synthesized by reverse suspension polymerization. The structure of the product was characterized by IR, SEM and TGA, and the adsorption capacity of the product was studied. It was found that when the amount of modified fulvic acid was 0.5000 g / L of CD ~ (2) ion (3.0 g / L), the dosage of ethylenediamine was 20 mL, the reaction time was 12 h, and the reaction temperature was 60 鈩，

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