布鲁克红外光谱培训 课件

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1、傅立叶红外光谱介绍电磁波GammaRayX-RayUVInfraredMicroWaveShortWaveRadioWavesEnergy[eV]Wavenumber[cm-1]Wavelength[m]Visible光与分子的作用分子激发产生振动振动的种类?伸缩振动对称伸缩振动不对称伸缩振动例如:水变形振动水的红外图15002000250030003500wavenumbercm-16065707580859095100Transmission[%]正己烷50多不同的振动正己烷10001500

2、20002500300035004000wavenumbercm-120406080100Transmission[%]C-HstretchC-Hdeformation„指纹区“红外光谱分为三个范围:15.000cm-14.000cm-1400cm-15cm-1NIRMIRFIR如何得到一张图色散型红外光谱仪傅立叶变换红外光谱仪色散型红外光谱仪DetectorDetector优点:-不需要计算机缺点:-速度慢-光通量低=>灵敏度低(S/Nratio)傅利叶变换红外光谱仪原理光源动镜定镜x分束器

3、LL+xx=0sourceDetectorfixedmirrorM1xBeamsplitterLL+xx=0例1:x=0,相长干涉结果1.Beampart(定镜)2.Beampart(动镜)sourceDetectorfixedmirrorM1xBeamsplitterLL+xx=1/2例2:x=1/2,相消性干涉0结果1.Beampart(定镜)2.Beampart(动镜)sourceDetectorfixedmirrorM1xBeamsplitterLL+xexam

4、ple3:x=,constructiveInterference0Resultingsignal1.Beampart(fixed)2.Beampart(movable)x=sourceDetectorfixedmirrorM1xBeamsplitterLL+xx=3/2example4:x=3/2,destructiveInterference0Resultingsignal1.Beampart(fixed)2.Beampart(movable)MirrormotionInt

5、ensity监测器信号FrequenceIntensity光源单色光源单色光源的调制信号EntstehungdesInterferogrammsMirrormotionIntensityResultingdetectorsignalFrequenceIntensity9条单一频率的光源MirrormotionIntensity总和:检测器信号FrequencyIntensity红外光源X,movingmirrorIntensity干涉图的来源透射光谱1.)Intheemptysamplecom

6、partmentanInterferogramisdetected.TheresultoftheFOURIERtransformationisR(ν).Fourier-Transformation5001000150020002500300035004000wavenumbercm-10.100.200.300.40SinglechannelintensityX,movingmirrorDetectorintensity2.)Asecondinterferogramisdetectedwith

7、thesampleplacedinthesamplecompartment.TheresultoftheFOURIERtransformationisS(ν).S(ν)showssimilaritiestothereferencespectrumR(v),buthaslowerintensitiesattheregionsthesampleabsorbsradiation.Fourier-Transformation5001000150020002500300035004000wavenumbe

8、rcm-10.100.200.300.40SinglechannelintensityX,movingmirrorDetectorintensity透射光谱ThetransmissionspectrumT(ν)iscalculatedastheratioofthesampleandreferencesinglechannelspectra:T(ν)=S(ν)/R(ν).5001000150020002500300035004000wavenumbercm-10.100.200.300.40Si