Depth profiling, analysis DRIFTS

Spectra. The energy spectrum is collected from the particles emitted from all depths simultaneously using a silicon surface barrier detector, electronic amplifiers, an analog-to-digital converter and a multichannel analyzer. A reference pulse is fed into the electronics to monitor the stability of the system thus allowing corrections to be made should electronic drift occur during the course of the measurement. Specific systems are described in the references (1 -4,6,7,12-17). By using computer-based data acquisition systems, the depth profile can be displayed at the time of analysis. 

PA-FTIR depth profiling results are consistent with the known layer stmcture of a packaging laminate film and an adhesive label [477]. Doublelayered PET/PET, PP/PET and PET/PP laminates were studied by PA-FTIR [478]. PA-FTIR and DSC identified a skin layer and a core in injection moulded PET plates [479]. Plastic-coated paper was analysed by both PA-FTIR and DRIFTS allowing for shallow- and deep-sampling, respectively [453]. PA-FTIR is also a suitable tool for the analysis of polymer films used as a barrier coating on beverage and food containers at variance to specular reflectance measurements surface flatness is not critical. 

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