静电纺丝法制备纳米纤维膜及其在电芬顿反应器中的应用毕业论文
2022-03-05 22:01:52
论文总字数:17186字
摘 要
在一般的电芬顿反应器中,阴极产生的H2O2由于副反应的发生会在阳极分解,从而降低电芬顿反应器的工作效率。本课题首次将静电纺丝法制备的聚偏氟乙烯(PVDF,Poly(vinylidene fluoride))纳米纤维膜作为隔膜引入电芬顿反应器中,隔开阴阳两极,有效阻止阴极生成的H2O2在阳极发生分解,从而提高电芬顿反应器的工作效率。
静电纺丝法制备的PVDF纳米纤维膜具有孔隙率高、孔径小、比表面积大、机械性能好、化学性质稳定等优点,而且膜制备的成本低、设备操作简单、可以连续生产。其作为一种重要的膜材料,已经成功地应用于化工、纺织、食品等多种领域。本课题对以下两个主要方面做出了探究和讨论:
第一,采用静电纺丝技术制备PVDF纳米纤维膜,用扫描电子显微镜(SEM,Scanning electron microscopy)对膜的微观形貌进行表征,讨论了不同纺丝条件对PVDF纳米纤维形貌及纤维直径分布的影响,确定了适用于本课题的最佳纺丝条件:纺丝液浓度为22wt% PVDF、纺丝电压为20kV、纺丝速度为0.001mm/s、接收距离为18cm。
第二,将最佳纺丝条件下制得的PVDF纳米纤维膜运用到电芬顿反应器中,以甲基橙为目标污染物对其进行降解,与无隔膜时的降解结果作对比得出:有隔膜时甲基橙的降解效率更高,从而证明了最佳纺丝条件确定的是合理的。
关键词:静电纺丝 聚偏氟乙烯 电芬顿 隔膜
Preparation of Nanofiber Membrane by Electrospinning and Its Application in Electro-Fenton Reactor
Abstract
In the conventional electro-Fenton reactor, the H2O2 produced by the cathode is decomposed at the anode due to the occurrence of side reactions, thereby reducing the efficiency of the electro-Fenton reactor. For the first time, the PVDF(Poly(vinylidene fluoride)) nanofiber membrane prepared by electrospinning was introduced into the electro-Fenton reactor as a separator to separate the cathode of the yin and yang, effectively preventing the decomposition of the H2O2 generated by the cathode in the anode, so as to improve the working efficiency of the electrocution.
The PVDF nanofiber membrane prepared by electrospinning has the advantages of high porosity, small pore size, large specific surface area, good mechanical properties and stable chemical properties. The cost of membrane preparation is low and the equipment is simple and can be continuously produced. As an important membrane material, it has been successfully applied in chemical, textile, food and other fields. This subject has explored and discussed the following two main aspects:
Firstly, the PVDF nanofiber membrane was prepared by electrospinning. The microstructure of the membrane was characterized by SEM(scanning electron microscopy). The morphology and fiber diameter distribution of PVDF nanofibers under different spinning conditions were discussed. The optimum spinning conditions were as follows: the spinning solution concentration was 22wt%, the spinning voltage was 20kV, the spinning speed was 0.001mm/s, and the receiving distance was 18cm.
Secondly, the PVDF nanofiber membrane prepared under the optimum spinning conditions was applied to the electro-Fenton reactor, and the methyl orange was used as the target pollutant to degrade it, and compared with the degradation result without the membrane : The degradation efficiency of methyl orange when the membrane is higher, thus proving that the optimum spinning conditions are reasonable.
Key Words: Electrospinning; Poly(vinylidene fluoride); Electro-Fenton; Separator
目 录
摘 要 I
Abstract II
第一章 文献综述 1
1.1 引言 1
1.2 PVDF的性质 1
1.3 静电纺丝装置的组成及工作原理 2
1.4 静电纺丝的工艺参数 2
1.5 电芬顿反应器工作原理 3
1.6 本课题研究内容 4
第二章 实验部分 5
2.1 实验试剂 5
2.2 实验仪器 5
2.3 确定最佳纺丝条件 6
2.3.1 确定最佳纺丝液浓度 6
2.3.2. 确定最佳纺丝电压 6
2.3.3. 确定最佳纺丝速度 7
2.3.4. 确定最佳接收距离 7
2.4 静电纺PVDF纳米纤维膜孔隙率的测定 7
2.4.1 制备静电纺PVDF纳米纤维膜 7
2.4.2 测定静电纺PVDF纳米纤维膜的孔隙率 8
2.5 探究甲基橙溶液浓度与其吸光度的关系 8
2.6 静电纺PVDF纳米纤维膜在电芬顿反应器中的应用 8
第三章 结果与讨论 10
3.1 实验结果 10
3.1.1 最佳纺丝条件 10
3.1.2 静电纺PVDF纳米纤维膜的孔隙率测定结果 14
3.1.3 甲基橙溶液浓度与其吸光度关系的测定结果 15
3.1.4 电芬顿反应降解甲基橙结果 15
3.2 结论 16
参考文献 18
致 谢 20
第一章 文献综述
1.1 引言
静电纺丝(Electroapinning)又被称为电纺丝,1934年出现首次描述塑料静电纺丝的关键专利,它的发明者是Anton Formhals[1,2]。目前,纳米纤维的合成方法有很多种,较为常见的方法包括分相法[3]、抽丝法[4]、模板合成法[5]、自组装法[6]等,但与前述几种方法相比,静电纺丝法的设备成本较低,生产操作较为简便,而且可以做到连续生产。因此,静电场纺丝技术引起了世界上很多国家对其深入研究的兴趣。
静电纺丝技术的基本原理是高压直流电产生强电场力使聚合物分子溶液或熔体喷射,并将其拉伸成为纤维。它可以将可溶或易熔聚合物加工成直径范围从几微米到几纳米的连续纤维。由此可见,该技术是连续生产纳米纤维的重要方法之一。静电纺丝法制备的纳米纤维膜具有孔隙率高、孔径小、过滤性强、纤维均一性好、精细程度高、机械性能好等优点[7,8]。
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