Research On The Separation Of Liquid Organic Mixture With Laser

Different materials have different absorptivity to the same length of optical wave. Within the infrared district, most of the energy absorbed by liquid is used to increase the kinetic energy of its molecule. Laser is good in Monochromaticity.Based on the facts above , pulsed laser can selectively acts on a certain substance , increases its molecular kinetic energy and helps the molecules escape out of the mixed liquid i.e. the substance is separated from the mixed liquid. The wavelength, pulse-width and peak power of laser should be appropriate.In this thesis, the design of the experimental system and scheme are included. The wavelength of the TEA- CO 2 laser used in this experiment is 10.6μm. Its pulse-width is around 10μs. And the energy of its single pulse can be adjusted from 6 J to 15 J. The experimental objects are methyl toluidine, acetylacetone, acetophenone and leucoline. They are mutually soluble and closed in boiling point and density. The substrate is made of KBr which absorbs little energy of 10.6μm laser and generates little heat. KBr substrate will not crack when hitted by laser pulse.Since the performance of the laser is not very stable and its pulse-width can just be adjusted in a very narrow interval, the experiment is taken by changing the pulse numbers. The samples are tested by infrared spectrometric analyzer and ultraviolet spectrograph. During the experiment, the phenomenon of "smoke", "ripple", "sound", "bubble" is appeared. The result shows that no chemical reaction set off during the experiment, and as the pulse numbers grows the composition percentage of the matter which "smokes" reduces. That is to say, the way of sepearation of mixed liquid by laser works.The absorption coefficients of liquid organic matter at 10.6μm are measured. The result shows it is not the only factor that affects the phenomenon of "smoke".