发布时间 : 星期一 文章江敏 - - 毕业论文 - 图文更新完毕开始阅读a7b871c7d4d8d15abf234e04
安徽工程大学机电学院毕业论文
氧化锌纳米材料的制备
摘 要
氧化锌纳米材料的几何尺寸在1~100nm范围内，具有表面效应、体积效应、量子尺寸效应、介电限域效应和宏观量子隧道效应等特性。表现出特别的力学、磁学、光学、热学和化学等特性。
本文的主要工作是对采用均匀沉淀法制备出纳米级别的氧化锌晶体的制备过程进行介绍，并讨论反应温度、乙酸锌浓度、反应物摩尔比、陈化时间等对纳米氧化锌产率的影响。在工艺条件为0.75mol/L乙酸锌与3.0mol/L尿素（比例为1:4）于90℃恒温磁力搅拌反应3小时（采用回流冷凝装置），其中表面活性剂浓度为0.002mol/L，保温陈化7小时，过滤、洗涤，60℃烘箱干燥，500℃马弗炉煅烧，所得产品符合要求，为50nm左右的氧化锌晶体。
实验现象表明陈化时间对氧化锌晶体的结晶度有很大影响。陈化时间短会造成纳米氧化锌晶体结晶度不够高，即氧化锌大部分以不定形态存在，晶体粒径小，延长陈化时间则会明显提高晶体的结晶度，增大晶体粒径。 关键词：氧化锌；纳米材料均；均匀沉淀法；结晶度
I
江敏：氧化锌纳米材料的制备
The preperation of ZnO nanomaterial
Abstract
The geometry size of ZnO nanomaterial is in the range of 1~100nm,with a sutface effect,volume effect,quantum size effect,dielectric confinement effect and macroscopic quantum tunneling effect and other characteristics.Showing a special machanics,magnetics,optical,thermal and chemical properties.
The main work in this paper is introducing the preparation process of nanoscale ZnO crystals by homogeneous precipitation method,and discuss the reaction temperature,reactant concenteation,reaction time,calcination temperature on the influence of nanoscale ZnO products.The experiments show that the process conditions of 0.7mol/L Zn(CH3COO)2 with 3.0mol/L urea(proportion is 1:4) reaction at 90℃ constant magnetic stirring reaction for 3 hours(With a reflux condenser unit),the surfactant concentration is 0.002mol/L,holding for 7 hours,filtering,washing,60℃ drying 4 hours,500℃ muffle calcining for 3 hours,the resulting product meets the requirements for paper,the crystal grain size of ZnO is about 50nm.
Experimental results show that the aging time has a great influence on thecrystallinity of ZnO crystal.A short aging time will lead to a low crystallinity of ZnO crystal, Most of the ZnO exist with amorphous state, the crystal grain size is small, the aging time is extended significantly improve the crystallinity of the crystal, the crystal grain size increases.
Key words:ZnO;nanomaterials;homogeneous precipitation method;degree of crystallinity
II
安徽工程大学机电学院毕业论文
目录
摘 要 ........................................................................................................................ I Abstract ........................................................................................................................ II 引言 .......................................................................................................................... - 1 - 第1章 文献综述 .................................................................................................... - 2 -
1.1 氧化锌纳米材料的结构............................................................................ - 2 - 1.2 氧化锌纳米材料的性质与应用................................................................ - 3 -
1.2.1 氧化锌纳米材料的基本物理性质................................................. - 3 - 1.2.2 氧化锌纳米材料的特殊性能及应用[4] ......................................... - 3 - 1.3 研究意义与内容........................................................................................ - 4 - 第2章 均匀沉淀法制备纳米氧化锌晶体 ............................................................ - 6 -
2.1实验方法的选择......................................................................................... - 6 - 2.2 实验部分.................................................................................................... - 6 -
2.2.1 实验原理......................................................................................... - 6 - 2.2.2实验药品.......................................................................................... - 7 - 2.2.2实验及分析仪器.............................................................................. - 7 - 2.3实验方法..................................................................................................... - 7 - 2.4 表征方法.................................................................................................... - 8 - 第3章 结果与讨论 ................................................................................................ - 9 -
3.1 反应温度的影响........................................................................................ - 9 - 3.2反应物摩尔比的影响................................................................................. - 9 - 3.3 乙酸锌浓度的影响.................................................................................. - 10 - 3.3 陈化时间的影响...................................................................................... - 10 - 结论 ........................................................................................................................ - 14 - 致谢 ........................................................................................................................ - 15 - 参考文献 ................................................................................................................ - 16 -
III
江敏：氧化锌纳米材料的制备
插图清单：
图1-1 ZnO晶体结构..................................................................................................-2- 图1-2 ZnO晶体结构在C(00001)面的投影...............................................................-2- 图1-3 氧化锌3D结构图...........................................................................................-3- 图3-1 陈化1小时的氧化锌X射线衍射结果.......................................................-11- 图3-2 陈化7小时的氧化锌X射线衍射结果.......................................................-11- 图3-3 氧化锌SEM检测结果(1).............................................................................-12- 图3-4 氧化锌SEM检测结果(2).............................................................................-12-
IV