TIME-RESOLVED RESONANCE RAMAN-SPECTROSCOPY USING A FAST MIXING DEVICE

A new fast mixing device has been developed. Our attention has been paid to improving the apparatus design in order to decrease the mixing dead time and to enhance the mixing efficiency. We modified and, mainly, simplified the system proposed by Clegg. The new device comprises two concentric tubes and a platinum spherical ball with a single piece of Teflon used as a support housing. Mixing is thus performed by the induced turbulent flow which can be generated by forcing a liquid stream to flow through channels between a Pt ball and a glass wall. This device offers many advantages relative to conventional mixing devices. The 99% mixing time for the device has been found to be 30 - 80 mus, which is at least a factor of 10 faster than the older devices. This technique can be applied using any type of fast reaction, solvent or laser. The stability of the stream and the excellent reproducibility allow measurements of the rate constants of very fast reactions.