Singlet Oxygen Production
Research into Physical Processes of Singlet Oxygen Formation in Electric Gas Discharges
Tech Area / Field
- PHY-PLS/Plasma Physics/Physics
3 Approved without Funding
TRINITI, Russia, Moscow reg., Troitsk
- Moscow State University / Institute of Nuclear Physics, Russia, Moscow
The purpose of the project is to investigate physical processes of the formation and quenching of singlet oxygen (SO) in different types of gas discharge.
The interest in these investigations is based on demands to use the SO for medical purposes for treatment of trophic and burn ulcers, in pulmonology. It is also based on the role of SO in processes of dynamics of an ozone layer of the Earth. A possibility is also considered of a replacement of ozone with the singlet oxygen in some manufacturing processes implementing oxidizing. The essential interest in SO is connected with chemical oxygen-iodine lasers (СOIL), having been developed during the last decade, where the atoms of iodine are excited due to resonant power transfer from molecular oxygen in a singlet state.
At present to produce SO the chemical singlet oxygen generator (SOG) are used where the singlet oxygen is produced as a result of reaction of gaseous chlorine with aqueous solution containing hydrogen peroxide and an alkali. The basic shortcoming of a chemical SOG is the use of chlorine which is a highly toxic gas. It restricts a feasibility of such SOG `s in manufacturing processes. This shortcoming can be avoided in electric-discharge SOG where the singlet oxygen is produced in an electric discharge in oxygen containing gas mixtures. At present the physical processes of formation and quenching of singlet oxygen are not sufficiently explored. It does not allow to develop a commercial electric-discharge SOG. Therefore it is an actual task to formulate on the basis of research of physical processes of formation and quenching of the singlet oxygen in different types of gas discharge the principles of generation of singlet oxygen by an electric-discharge method.
In this Project we intend to utilize the long-term experience in investigating the gas discharges in different media, and various gas discharge techniques previously used by the participants of the Project to excite the working media of gas electric-discharge lasers.
Under this Project it is supposed to explore the different types of a gas discharge in oxygen containing mixtures, including: a non self-sustained discharge controlled by an electron beam, diffusive capacity discharge of alternating current, pulsed volume discharge with ultraviolet (UV) pre-ionization, surface discharge in submillimeter slot-hole gaps etc. The results of these investigations will allow to formulate the physical principles of generation of the high content SO at pressures of several dozens of Torr.
The participants of the Project possess considerable scientific and technological potential; they have highly qualified and skilled personnel in the field of laser physics, plasma physics, gas dynamic, applied mathematics. Besides, during previous years cooperation has been established with leading organizations in Russia in the field of development of a laser technology, gas-discharge devices and scientific instrumentation. All this allows to solve the task of carrying out the related R&D and creation of the experimental setups during a short period of time.
In the course of the works we intend:
1. To extend the available database on reaction rates of electronic kinetics taking place during production of the singlet oxygen via special experiments to be carried out in gas discharges in oxygen-containing mixtures. To carry out the experimental investigations of processes of singlet oxygen formation and loss in volume and on special coatings. To reveal the possibility of reaching a theoretical limit determined by the electronic kinetics of the singlet oxygen, and also the possibility of making new materials providing the nonequilibrium catalysis of the singlet oxygen on a surface.
2. To carry out experimental investigations of processes and singlet oxygen formation efficiency in:
- Non self-sustained discharge controlled by an electron beam;
- Diffusive capacity discharge of alternating-current at frequency of ~ 15 kHz;
- Pulsed volume discharge with UV preionization;
- Surface discharge in slot-hole submillimeter gaps;
- Open discharge.
3. To explore temperature regimes of singlet oxygen generation in a gas discharge and to analyze the possibility to control the gas cooling rate.
4. To determine experimentally conditions for obtaining high (> 30 %) content of the singlet oxygen at several dozens of Torr pressures.
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