REACTION MONITORING OF IONIC LIQUID SYNTHESIS USING RAMAN SPECTROSCOPY

In this project, the viability of Raman spectroscopy is studied during real-time
reaction monitoring of synthesis of Ionic Liquid (IL). The vital IL for this project is
l-butyl-3-methylimidazolium tetrachloroferrate, [bmim] FeCU which is synthesized
from the reaction of l-butyl-3-methylimidazolium chloride, [bmim] CI" and Iron (III)
Chloride, FeCU. The characteristic of the Raman spectra throughout the reaction is
studied by using a series of in-situ data to analyse the composition qualitatively in
order to determine the individual reactant, intermediate, and product during the
reaction. Raman spectroscopy is an influential instrument for researchers if it can be
applied for the real-time monitoring synthesis of [bmim] FeCU". Undesired
impurities such as l-butyl-3-methylimidazolium, [bmim] Fe2Cl7" ions would form
during the reaction when the ratio of [bmim] CI" to FeCU is larger than 1 and Raman
spectroscopic monitoring can help in determining it occurrence. These possible
impurities has unknown properties and effect on the efficiency of [bmim] FeCU* in
its application as a catalyst or a solvent extractor need to be studied. The project used
Taguchi method as its design of experiment and 2 parameters is introduced. Reactant
ratio from 1:1 to 1:2 and monitoring time from 1 to 4 hours is manipulated in L16
Taguchi Orthogonal Array. Standard room temperature and pressure of 25°C and 1
aim is assumed to be constant throughout the experiment. The result can be observed
at the Raman excitation peak at the range of 50-500 cm'1. From the data obtained,
[bmim] FeCU production in one-to-one ratio of synthesis does not contain any
impurities while one-to-two synthesis ratio shows the difference in the spectral peak
produced which indicates the additional formation of [bmim] Fe2Cl7~. This finding
concludes that Raman spectroscopy is proven to be a viable method in analysing the
[bmim] FeCU reaction monitoring.