论文总字数：24654字

摘 要

本文采用液相还原法，选用抗坏血酸还原亚硒酸制备纳米硒粉。首先，在测定溶液的pH-Zeta电位图的基础上，确定分散剂的类型以及分散时溶液的pH值。其次，采用TEM和激光粒度分析表征纳米硒粉的一次粒径和团聚体粒径。然后，通过采用分光光度计测试溶液的吸光度确定不同分散体系的分散稳定性。最后，通过抗菌圈实验测试加入不同分散剂后纳米硒对大肠杆菌、金黄色葡萄球菌、绿脓杆菌和枯草芽孢杆菌四种细菌的抗菌性能的影响。研究表明：

1. 在pH=6时，Zeta电位的绝对值最大为14.85mV，此时纳米硒物质表层带负电荷。因此选择实验所用的分散剂为阳离子型CTAB、非离子型Span80和有机高分子PEG-2000、PVP表面活性剂以及分散时溶液的pH值为6。
2. 未原位分散的纳米硒粒子粒径分布为105nm~252nm，平均粒径为168nm，纳米硒粒子的形貌为不规则的近球形，粒子之间团聚现象严重。采用3wt%分散剂CTAB、PVP、Span80和PEG2000原位分散制备的纳米硒粒子粒径分布分别为22nm~106nm、46nm~140nm、27nm~118nm和54nm~96nm，平均粒径分别为52nm、89nm、80nm和73nm，分散过后纳米硒粒子形貌为较规则的球形，粒子之间有较少的团聚现象。
3. 随分散时间增加，CTAB的分散效果呈增大的趋势，而Span80、PVP和PEG2000则呈先增大后减小的趋势；本文确定纳米硒粉较优的分散工艺为3wt%CTAB，超声分散40min。
4. 在研究纳米硒粉原位分散制备时，CTAB的添加量和纳米硒的浓度对四种细菌抗菌性能的影响发现，当CTAB添加量为1wt%、3wt%、5wt%、7wt%、9wt%时，对金黄色葡萄球菌、枯草芽孢杆菌和绿脓杆菌的最低抑制浓度为10μg/mL、10μg/mL和100μg/mL；当CTAB添加量分别为1wt%、3wt%、5wt%、7wt%时，对大肠杆菌的最低抑制浓度为50μg/mL，当CTAB浓度增大到9wt%时，对大肠杆菌的最低抑制浓度为10μg/mL。

关键词：纳米硒 制备 分散 抗菌性能

Preparation of Nano-selenium by In-situ Dispersion in Liquid Phase and Its Antibacterial Properties

Abstract

In this paper, liquid phase reduction method was used, and Vc was used to reduce selenite to prepare nano-selenium powder. Firstly, based on the pH-Zeta potential map of the solution, the type of the dispersant and the pH of the solution at the time of dispersion were determined. Secondly, the primary particle size and agglomerate particle size of the nano-selenium powder were characterized by TEM and laser particle size analysis. The dispersion stability of the different dispersions was then determined by measuring the absorbance of the solution using a spectrophotometer. Finally, the effect of nano-selenium on the antibacterial properties of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis was tested by antibacterial circle experiments. The studies have shown that:

(1)The absolute value of Zeta potential is the highest at pH of 6, which is 14.85mV. And the surface layer of nano-selenium has negative charge. Therefore, the dispersing agents used in the experiment were cationic CTAB, Nonionic Span80 and organic polymer PEG-2000, PVP surfactants, and the pH value was 6.

(2)The size distribution of nano-selenium particles not dispersed in situ is 105nm~252nm, and the average particle size is 168nm. The morphology of nano-selenium particles is irregular near-spherical shape, and the phenomenon of agglomeration between particles is serious. The particle size distribution of nano-selenium particles prepared by in-situ dispersion of 3wt% dispersants CTAB, PVP, Span80 and PEG2000 were 22nm~106nm, 46nm~140nm, 27nm~118nm and 54nm~96nm, respectively. The average particle size was 52nm and 89nm, respectively. At 80 nm and 73 nm, after dispersing, the morphology of the nano-selenium particles is a relatively regular sphere, and there is less agglomeration between the particles.

(3)With the increase of dispersion time, the dispersion effect of CTAB increased, while Span80, PVP and PEG2000 increased first and then decreased. The better dispersion process was determined to be 3wt% CTAB and ultrasonic dispersion for 40min.

(4)Through the antibacterial circle test of the samples before and after in situ dispersion, it was found that the nano-selenium dispersed by CTAB had antibacterial effect. The effects of the amount of CTAB and the concentration of nano-selenium on the antibacterial properties of the four bacteria were studied when the amount of CTAB was 1wt%, 3wt%, 5wt%, 7wt% and 9wt%, respectively.The minimum inhibitory concentrations of Bacillus subtilis and Pseudomonas aeruginosa were 10μ g/mL,10 μg/mL and 100 μg/mL;when the amount of CTAB was 1wt%,3wt%, 5wt% and 7wt%, the minimum inhibitory concentration of E.coli is 50 μg / mL,. When the CTAB concentration was increased to 9% by weight, the minimum inhibitory concentration for E.coli was 10 μg/ mL.

Key words: Nanometer selenium Lining-up Disperse Antibacterial property

目 录

摘 要 I

Abstract II

第一章 绪 论 1

1.1论文研究的目的和意义 1

1.2硒简介 2

1.2.1硒的发展 2

1.2.2硒与纳米硒 2

1.3纳米硒的生物学功能 2

1.3.1机体抗氧化系统 2

1.3.2机体免疫功能 3

1.3.3抗癌作用 3

1.3.4抗糖尿病作用 3

1.3.5在动物生产中的应用 3

1.3.6抗菌作用 3

1.4纳米硒的制备 4

1.4.1溶胶法 5

1.4.2固相法 5

1.4.3液相法（模板法） 5

1.5纳米硒的分散 6

1.6小结 6

第二章 实验方法及内容 7

2.1 实验原料及仪器 7

2.1.1实验原料 7

2.1.2实验仪器 7

2.2实验方法 8

2.2.1纳米硒的制备及表征 8

2.2.2纳米硒粉的分散工艺及其分散稳定性表征 9

2.2.3纳米硒的抗菌圈实验与抑菌试验 10

第三章 结果分析及讨论 11

3.1纳米硒的制备及表征 11

3.1.1纳米硒的XRD分析 11

3.1.2分散剂的选择 11

3.2纳米硒的TEM形貌及一次粒径、团聚体粒径分析 12

3.3纳米硒分散稳定性的表征 14

3.3.1吸光波长的确定 14

3.3.2吸光度的测定 15

3.4纳米硒的抗菌性能测试 17

3.4.1抗菌圈测试 17

3.4.2纳米硒对大肠杆菌的抗菌性能 18

3.4.3纳米硒对金黄色葡萄球菌的抗菌性能 19

3.4.4纳米硒对枯草芽孢杆菌的抗菌性能 19

3.4.5纳米硒对绿脓杆菌的抗菌性能 20

3.5不同分散剂制备纳米硒及CTAB抑菌原理分析 22

第四章 结 论 23

参考文献 24

致 谢 27

第一章 绪 论

1.1论文研究的目的和意义

硒是一种人体不可缺少而又不可过量的非金属元素，对人体健康至关重要，在生命体中有抗氧化能力、免疫功能、抗病毒、保护心血管、抗癌等诸多功效。同时，缺硒可使心血管疾病、癌症、大骨节病等疾病的发病率显著升高，为了预防这些疾病，适当补硒是有必要的。但是，硒在生物体内安全的剂量范围很窄，超过一定的量就会产生毒性^[1]，这就限制了传统的硒化合物在临床疾病的防治方面的运用。

由于对高效低毒硒制剂的需求，纳米硒登上了硒制剂的舞台，纳米硒粉指的是一次颗粒尺寸小于100nm的晶体硅颗粒，它具有分散性好、比表面积大、性能稳定等特点。纳米硒粉不仅具有硒的生物学特性，同时具备了纳米粒子的小尺寸效应、表面效应、量子尺寸效应等^[2]。

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