**2.3. FTIR analysis**

Potassium bromide (KBr) pellet method was used for FTIR spectroscopy. Thin discs of KBr were prepared by placing a small amount of KBr into the die set and were subjected to a pressure of 8 tons. This pressure caused the KBr to re-crystallize to form thin transparent discs. These discs were used to obtain the background. A small amount of test sample powder was added to KBr and thin discs were prepared by a similar procedure.
