(a) Interactions between CO2 and polymers are important for polymer processing with high-pressure or supercritical fluid CO2. Why is the degeneracy of the bending vibrational mode of CO2 removed when it is absorbed into polymers that contain carbonyl functional groups? Explain how it is observed spectroscopically and the implications of such interactions. (b) Which spectroscopic technique would you use to observe symmetric stretching vibration of CO? Explain why. v, (1388 cm) (c) What is the difference between Attenuated Total Reflection (ATR)-FTIR spectroscopy and confocal Raman microscopy with regard to the probing depth into polymeric samples that can be analysed by these techniques? Support explanations with corresponding equations or/and schematics as appropriate. (d) Explain the main differences between micro ATR-FTIR spectroscopic imaging and macro ATR-FTIR spectroscopic imaging. What are the main applications of each of these methods?