磁性镍锌铁氧体纳米材料的制备及应用

发布时间：2018-01-03 10:29

本文关键词：磁性镍锌铁氧体纳米材料的制备及应用　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：磁性镍锌铁氧体纳米材料具有饱和磁化强度高、居里温度高、化学稳定性好、矫顽力低、比表面积大等很多优点,是重要的有前景的磁性纳米材料之一,可广泛应用于环境污水处理和生物领域。本文采用快速燃烧法和柠檬酸-凝胶法制备了磁性镍锌铁氧体纳米材料,并采用XRD、SEM、TEM、BET和VSM等分析方法对其进行了表征,并研究了镍锌铁氧体在污水处理和生物上的应用,其主要结论如下:1.以无水乙醇为溶剂,采用快速燃烧法制备了磁性Ni_(0.5)Zn_(0.5)Fe_2O_4纳米材料。发现磁性Ni_(0.5)Zn_(0.5)Fe_2O_4纳米材料在10 mL无水乙醇和400℃条件下即可形成,且无水乙醇的量是影响Ni_(0.5)Zn_(0.5)Fe_2O_4纳米材料性能的关键因素。揭示了无水乙醇的量对Ni_(0.5)Zn_(0.5)Fe_2O_4纳米材料性能影响规律:随着无水乙醇体积从10 mL到30 mL的增加,在400℃下煅烧2 h得到的磁性Ni_(0.5)Zn_(0.5)Fe_2O_4纳米材料的平均颗粒尺寸从14.9nm增加至18.3 nm,饱和磁化强度从27.1 Am2/kg增加至105.2 Am2/kg,比表面积在无水乙醇的量为15 m L时,达到最大69.7 m2/g;实现了磁性镍锌铁氧体纳米材料的快速燃烧可控制备。2.采用响应面法优化了磁性Ni_(0.5)Zn_(0.5)Fe_2O_4/SiO2纳米复合材料吸附中性红工艺,并研究了其吸附动力学和吸附等温线。通过响应面软件对实验数据进行统计分析,确定了磁性Ni_(0.5)Zn_(0.5)Fe_2O_4/SiO2纳米复合材料吸附中性红的优化条件:中性红水溶液pH为5.4,纳米复合材料中SiO2含量为17.3%,纳米复合材料的煅烧温度为581℃,且优化条件下纳米复合材料对中性红的最大吸附量高达39.9 mg/g。同时,基于实验数据的模拟计算发现,准二级动力学模型可以很好的描述磁性Ni_(0.5)Zn_(0.5)Fe_2O_4/SiO2纳米复合材料室温下吸附中性红的动力学过程,磁性Ni_(0.5)Zn_(0.5)Fe_2O_4/SiO2纳米复合材料吸附中性红的等温线符合Redlich-Peterson模型,揭示了磁性Ni_(0.5)Zn_(0.5)Fe_2O_4/SiO2纳米复合材料表面的多样性,并根据模型机理推断出磁性Ni_(0.5)Zn_(0.5)Fe_2O_4/SiO2纳米复合材料对中性红的吸附为单层和多层的混合吸附模式。3.青霉素酰化酶在磁性Ni_(0.5)Zn_(0.5)Fe_2O_4@SiO2纳米复合材料上的固定化。采用快速燃烧法成功制备了磁性Ni_(0.5)Zn_(0.5)Fe_2O_4/SiO2纳米复合材料,并采用戊二醛对磁性Ni_(0.5)Zn_(0.5)Fe_2O_4@SiO2纳米复合材料进行表面改性,进而在其表面成功固定了青霉素酰化酶,并探讨了固定化青霉素酰化酶和游离青霉素酰化酶在不同pH和温度下的活性。经比较发现,固定化的青霉素酰化酶的活性受pH和温度的影响程度比游离青霉素酰化酶大大降低,表现出良好的酸碱稳定性和热稳定性;固定于磁性纳米材料之上的青霉素酰化酶循环使用12次后,相对活性依然保持63.5%,表现出良好的固定化酶循环利用率。
[Abstract]:Magnetic properties of Ni Zn ferrite nano material with high saturation magnetization, high Curie temperature, good chemical stability, low coercivity, high specific surface area and many other advantages, is one of the most promising nano magnetic materials can be widely used in environmental and biological sewage treatment field. This paper adopts the rapid combustion method and citric acid sol-gel method magnetic Ni Zn ferrite nano materials were prepared, and the use of XRD, SEM, TEM, BET and VSM analysis methods were used to characterize them, and study the application of Ni Zn ferrite in wastewater treatment and biological, the main conclusions are as follows: 1. using anhydrous ethanol as solvent, using fast the combustion of magnetic Ni_ was prepared (0.5) Zn_ (0.5) Fe_2O_4 nano material. It is found that the magnetic Ni_ (0.5) Zn_ (0.5) Fe_2O_4 nano materials can be formed in 10 mL ethanol and 400 DEG C, and the amount of ethanol is Ni_ (0.5) Zn_ (0.5) Fe_2O_4 nano materials The key performance factors. Reveals the ethanol amount on Ni_ (0.5) Zn_ (0.5) properties of Fe_2O_4 nano materials with anhydrous ethanol increased from 10 mL to 30 mL, was annealed at 400 2 h the magnetic Ni_ (0.5) Zn_ (0.5) Fe_2O_4 nano materials were flat the particle size increased from 14.9nm to 18.3 NM, the saturation magnetization increased from 27.1 Am2/kg to 105.2 Am2/kg, the specific surface area in the volume of anhydrous alcohol is 15 m L, reached a maximum of 69.7 m2/g; the rapid combustion of magnetic Ni Zn ferrite nano materials can be controlled by surface preparation of.2. was optimized by Ni_ (magnetic response 0.5) Zn_ (0.5) Fe_2O_4/SiO2 nano composite material of neutral red adsorption process, and studied its adsorption kinetics and adsorption isotherm. Through statistical analysis of experimental data the response surface software, determine the magnetic properties of Ni_ (0.5) Zn_ (0.5) Fe_2O_4/ SiO2 nanocomposite adsorption of neutral red The optimal conditions of neutral red pH aqueous solution was 5.4, the content of SiO2 in the composite is 17.3%, calcination temperature of nanocomposites is 581 DEG C, and the optimization of the maximum adsorption capacity of nano composite materials under the condition of neutral red as high as 39.9 mg/g. at the same time, based on the experimental data of simulation calculation found that the quasi two level dynamics the model can describe well the magnetic properties of Ni_ (0.5) Zn_ (0.5) adsorption kinetics of neutral red at room temperature of Fe_2O_4/SiO2 nano composite materials, magnetic properties of Ni_ (0.5) Zn_ (0.5) adsorption isotherms of Fe_2O_4/SiO2 nanocomposites of neutral red with the Redlich-Peterson model, reveals the magnetic properties of Ni_ (0.5) Zn_ (0.5) surface diversity Fe_2O_4/SiO2 nano composite materials, and according to the mechanism model to infer the magnetic properties of Ni_ (0.5) Zn_ (0.5) Fe_2O_4/SiO2 nano composite materials on the adsorption of neutral red as the mixed monolayer and multilayer adsorption model of.3. in penicillin acylase The magnetic Ni_ (0.5) Zn_ (0.5) immobilized on nano Fe_2O_4@SiO2 composite materials. With the rapid combustion of magnetic Ni_ were successfully prepared (0.5) Zn_ (0.5) Fe_2O_4/SiO2 nano composite material, and using glutaraldehyde on magnetic properties of Ni_ (0.5) Zn_ (0.5) surface modified Fe_2O_4@SiO2 nano composite materials, and on the surface of successfully immobilized penicillin acylase, and discusses the activity of immobilized penicillin acylase and free penicillin acylase in different pH and temperature. The results showed that penicillin acylase immobilized activated by pH and temperature influence than free penicillin acylase greatly reduced, showing good pH stability and thermal stability; fixed on magnetic nano materials of penicillin acylase recycled 12 times, the relative activity remained 63.5%, showing good immobilized enzyme recycling rate.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM277;TB383.1

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