脱水过程热分析

1、综合实验五 CuSO4·5H2O脱水过程热分析实验实验目的1、熟悉热重（TG）和差示扫描量热法（DSC）的基本原理；2、掌握CuSO4·5H2O加热脱水过程TG-DSC曲线的分析方法。实验原理热分析是在程序控温条件下，测量样品的质量与吸热量随温度变化关系的一门技术，主要用于对物质的相变、吸附、脱水、分解、氧化和还原等过程的分析和研究。热分析仪原理如下图所示：CuSO4·5H2O在加热的过程中的热重(TG)、热重微商(DTG)和差示扫描量热值(DSC)的曲线如下：TG曲线能反映加热过程中系统质量变化的情况，DTG曲线能辅助分析质量变化的细节，DSC曲线的峰面积为系统

2、的吸热量。从室温加热到850度的过程中，CuSO4·5H2O要发生以下变化：脱水过程：CuSO4·5H2O CuSO4·3H2O+2 H2O(g) CuSO4·3H2O CuSO4·H2O+2 H2O(g)CuSO4·H2O CuSO4+H2O(g)分解过程：CuSO4 CuO + SO2 (g) + 1/2O2 (g) （从TG-T 图中可查出这些变化过程对应的温度区间）实验步骤本实验重点研究CuSO4·5H2O脱水过程中失重和吸热的情况，具体实验过程如下：运行热分析采样软件： 设置实验条件 将CuSO4·5H2

3、O装入坩埚中 称重，设置加热区间为室温400 加热 采集TG、DSC和样品温度的信息 运行数据处理软件：打开实验数据 对TG求导，绘出DTG曲线 对DSC脱水峰的面积进行积分实验结束：锁天平、停气、停水、关Ar气钢瓶的阀门、关掉水管的阀门、关闭计算机、关闭总电源。（具体做法见“CuSO4 ·5H2O脱水过程TG-DSC热分析实验操作过程”说明）数据处理与结论1.将实验结果图贴在实验报告中适当的位置（3张图）；1.将实验数据填入下表中：脱水过程123开始温度/T结束温度/T理论失重率/%实际失重率/%吸热量/ J/g思考题1. 将下面的一段英文翻译为中文，写在实验报告上，以便了解什么是

4、DSC.Differential scanning calorimetry (DSC) is a thermoanalytical technique in which the difference in the amount of heat required to increase the temperature of a sample and reference is measured as a function of temperature. Both the sample and reference are maintained at nearly the same temperatu

5、re throughout the experiment. Generally, the temperature program for a DSC analysis is designed such that the sample holder temperature increases linearly as a function of time. The reference sample should have a well-defined heat capacity over the range of temperatures to be scanned. The technique was developed by Watson et al. in 1964. The term DSC was coined to describe this instrument which measures energy directly and allows precise measurements of heat capacity.2.