论文总字数：33547字

摘 要

沉积物是湖泊生态与环境体系中重要的组成部分，对水环境质量和水体生态系统具有重要影响。研究沉积物中的电流过程与导电机制，对于开发适合沉积物大规模原位修复的技术和工艺具有重要的意义。该论文为了探究自然沉积物中的电流现象，探讨纳米导电菌丝与周围环境的导电机制，提出构建自然沉积物环境中典型的无机颗粒和有机导电菌丝（有机导体）体系，模拟建立由二氧化硅颗粒和有机纳米线导体（聚吡咯）所形成的复合体系的导电规律，并创新地首次提出采用电阻网络模型对该复合体系的电学性质进行了仿真与预测。

该项目首先建立了以聚吡咯纳米线与二氧化硅颗粒组成的复合体系来模拟自然沉积物，并从复合材料导电机理角度研究相关参数对该体系的导电性能的影响及变化规律。研究结果表明，在聚吡咯纳米线质量分数为9%时，微米级二氧化硅颗粒复合体系的电阻值明显低于纳米级的二氧化硅颗粒复合体系电阻率，但当聚吡咯纳米线质量分数逐渐增加，二氧化硅颗粒直径对于该复合体系的电阻率的影响不再明显。其次，压强对于该复合体系电阻率的影响也是随着聚吡咯质量分数的增加而逐渐减小。这代表了聚吡咯纳米线网络是该复合体系的主要导电通路。

另外，该文首次创新地构建了电阻网络模型对该复合体系的电学性质进行了仿真与预测。利用蒙特卡罗思想为指导建立了与本实验对象相对应的三维电阻网络模型，并利用Hspice软件对建立的电阻网络模型进行仿真，将仿真结果与所测量的复合材料电学性质进行了比较分析。仿真结果表明，聚吡咯纳米线与二氧化硅复合体系在相同尺寸不同比例以及相同比例不同尺寸的导电规律与实验结果具有较大的一致性，且预测了渗滤阈值的存在。该结果也印证了计算机模拟的电阻网络模型具备良好的拓展性与发展空间，可以应用到沉积物的导电网络中。该研究方法可以预测导电网络的相关规律，对实际沉积物的导电网络规律具有借鉴意义。

关键词：聚吡咯，复合材料，二氧化硅，三维电阻模型

Abstract

Sediments are an important part of the lake's ecological and environmental systems, and have important implications for water environment quality and water ecosystems. The study of current processes and electrical conductivity in sediments is of great significance for the development of techniques and processes suitable for large-scale in-situ remediation of sediments. In order to investigate current phenomena in natural sediments, this paper explores the conductive mechanism of nano-conductive mycelium and its surroundings, and proposes to construct a system of inorganic particles and organic conductive mycelium (organic conductors) typical in the environment of natural sediments. The electrical conductivity of the composite system formed by the silicon oxide particles and the organic nanowire conductor (polypyrrole) was innovatively proposed for the first time using a resistance network model to simulate and predict the electrical properties of the composite system.

The project first established a composite system composed of polypyrrole nanowires and silica particles to simulate natural sediments, and from the perspective of the composite material conduction mechanism, the influence of relevant parameters on the electrical conductivity of the system and the law of variation were studied. The results show that when the mass fraction of polypyrrole nanowires is 9%, the resistance value of the micron-sized silica particle composite system is obviously lower than that of the nano-sized silica particle composite system, but when the polypyrrole nanowire mass fraction Increasing gradually, the effect of silica particle diameter on the resistivity of the composite system is no longer obvious. Secondly, the effect of pressure on the resistivity of the composite system also decreases with the increase of the polypyrrole mass fraction. This represents that the polypyrrole nanowire network is the main conductive path of the composite system.

In addition, this paper innovatively constructed a resistance network model to simulate and predict the electrical properties of the composite system. Using Monte Carlo idea as a guide to establish a three-dimensional resistance network model corresponding to the experimental object, and using the Hspice software to simulate the established resistance network model, and comparing the simulation results with the measured electrical properties of the composite material. The simulation results show that the conductivity of polypyrrole nanowires and silica composite system in the same size and in different proportions and the same proportion of different size of the conductivity and experimental results have greater consistency,and predicted the presence of a percolation threshold. This result also confirms that the computer simulation of the resistance network model has good scalability and development space, and can be applied to the conductive network of deposits. The research method can predict the relevant laws of the conductive network, and has reference significance for the actual network of conductive sediments.

Keywords: polypyrrole, composite material, SiO₂, three-dimensional resistance model

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1水体沉积物污染 1

1.2生物修复与导电网络 1

1.3复合材料 2

1.3.1 复合材料概述 2

1.3.2复合材料导电机理 3

1.4聚吡咯概述 4

1.5聚吡咯/无机纳米粒子复合材料研究进展 5

1.6本文的研究内容与意义 6

第二章 聚吡咯/二氧化硅复合材料研究 8

2.1 聚吡咯纳米线的制备 8

2.1.1制备方法背景 8

2.1.2 电化学工作站的介绍 9

2.2.1 实验试剂 10

2.2.2 实验仪器 10

2.2.3 聚吡咯纳米线的制备 10

2.2.4 聚吡咯/二氧化硅复合材料的制备 11

2.2.5 聚吡咯/二氧化硅复合材料的电学性质测量 11

2.3 实验结果分析 13

2.3.1 二氧化硅颗粒与聚吡咯纳米线之间的电阻率 13

2.3.2 FT-IR原子基团分析 16

2.3.3微观形貌分析 17

2.3.4 元素组成分析 17

2.4 本章小结 19

第三章 聚吡咯/二氧化硅复合材料电阻的模拟研究 20

3.1 背景简介 20

3.1.1 蒙特卡罗（Monte Carlo method）方法简介 20

3.1.2 三维电阻网络模型介绍 20

3.1.3 SPICE语言与相关平台简介 21

3.2 实验部分 21

3.2.1 电阻网络拓扑结构 21

3.2.2 电阻网络仿真 22

3.2.3仿真结果分析比较 22

3.3 本章小结 23

第四章 全文总结与展望 24

4.1 总结 24

4.2 展望 25

致谢 26

参考文献 27

附录 32

绪论

1.1水体沉积物污染

水体沉积物对于自然水质有着直接或间接的影响，一方面，水底沉积物可能是污染的直接来源或是有害物质的携带者。另一方面，水底沉积物可以灵敏的反应水质状况。事实上，城市化，工业化，矿物开采等人类活动加速了水体沉积物污染的积累，加快了环境恶化的速度。水底沉积物的污染种类有许多，就目前而言关于有机物与重金属的污染最为严重且影响最为广泛，因此也更为容易引起研究人员的注意^[1]。

由于世界塑料产量在不断上升，在2011年时就达到了2.8亿吨，自然水域中出现了大量的处理不当的塑料废物，在自然环境中这些塑料废物难以降解，通常会分解为微米级别的微片塑料。这些微米塑料片的来源主要来自于化妆品中的弹性颗粒与来自织物中的微弹性纤维如聚酯和聚酰胺。而研究表明大量多毛类，双壳类，棘皮动物和桡足类动物在其至少一个生命阶段里会摄入这些微片塑料，而这些废物的去处通常被动物以排便方式排出或留在身体中^[2]。

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