江敏------毕业论文.doc

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 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 目录 摘 要 I Abstract II 引言 - 1 - 第1章 文献综述 - 2 - 1.1 氧化锌