脫水過(guò)程熱分析

1、綜合實(shí)驗(yàn)五 CuSO4·5H2O脫水過(guò)程熱分析實(shí)驗(yàn)實(shí)驗(yàn)?zāi)康?、熟悉熱重（TG）和差示掃描量熱法（DSC）的基本原理；2、掌握CuSO4·5H2O加熱脫水過(guò)程TG-DSC曲線的分析方法。實(shí)驗(yàn)原理熱分析是在程序控溫條件下，測(cè)量樣品的質(zhì)量與吸熱量隨溫度變化關(guān)系的一門(mén)技術(shù)，主要用于對(duì)物質(zhì)的相變、吸附、脫水、分解、氧化和還原等過(guò)程的分析和研究。熱分析儀原理如下圖所示：CuSO4·5H2O在加熱的過(guò)程中的熱重(TG)、熱重微商(DTG)和差示掃描量熱值(DSC)的曲線如下：TG曲線能反映加熱過(guò)程中系統(tǒng)質(zhì)量變化的情況，DTG曲線能輔助分析質(zhì)量變化的細(xì)節(jié)，DSC曲線的峰面積為系統(tǒng)

2、的吸熱量。從室溫加熱到850度的過(guò)程中，CuSO4·5H2O要發(fā)生以下變化：脫水過(guò)程：CuSO4·5H2O CuSO4·3H2O+2 H2O(g) CuSO4·3H2O CuSO4·H2O+2 H2O(g)CuSO4·H2O CuSO4+H2O(g)分解過(guò)程：CuSO4 CuO + SO2 (g) + 1/2O2 (g) （從TG-T 圖中可查出這些變化過(guò)程對(duì)應(yīng)的溫度區(qū)間）實(shí)驗(yàn)步驟本實(shí)驗(yàn)重點(diǎn)研究CuSO4·5H2O脫水過(guò)程中失重和吸熱的情況，具體實(shí)驗(yàn)過(guò)程如下：運(yùn)行熱分析采樣軟件： 設(shè)置實(shí)驗(yàn)條件 將CuSO4·5H2

3、O裝入坩堝中 稱(chēng)重，設(shè)置加熱區(qū)間為室溫400 加熱 采集TG、DSC和樣品溫度的信息 運(yùn)行數(shù)據(jù)處理軟件：打開(kāi)實(shí)驗(yàn)數(shù)據(jù) 對(duì)TG求導(dǎo)，繪出DTG曲線 對(duì)DSC脫水峰的面積進(jìn)行積分實(shí)驗(yàn)結(jié)束：鎖天平、停氣、停水、關(guān)Ar氣鋼瓶的閥門(mén)、關(guān)掉水管的閥門(mén)、關(guān)閉計(jì)算機(jī)、關(guān)閉總電源。（具體做法見(jiàn)“CuSO4 ·5H2O脫水過(guò)程TG-DSC熱分析實(shí)驗(yàn)操作過(guò)程”說(shuō)明）數(shù)據(jù)處理與結(jié)論1.將實(shí)驗(yàn)結(jié)果圖貼在實(shí)驗(yàn)報(bào)告中適當(dāng)?shù)奈恢茫?張圖）；1.將實(shí)驗(yàn)數(shù)據(jù)填入下表中：脫水過(guò)程123開(kāi)始溫度/T結(jié)束溫度/T理論失重率/%實(shí)際失重率/%吸熱量/ J/g思考題1. 將下面的一段英文翻譯為中文，寫(xiě)在實(shí)驗(yàn)報(bào)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.