Volatile organic compounds, doped

J. H. Krech, S. L. Rose-Pehrsson, Detection of volatile organic compounds in the vapor phase using solvatochromic dye-doped polymers, Chimi. Acta34, 53-62 (1997). 

Environmental applications of metal-doped carbon gels can be divided between reactions carried out in the gas and aqueous phases. The former group includes volatile organic compound (VOC) oxidation (e.g., toluene and xylene oxidation) and NO reduction. The latter group includes the catalytic wet air oxidation (CWAO) of aniline solutions and advanced oxidation processes (AOPs) (e.g., catalytic ozonation and photooxidation of pollutants). 

Afterburning processes enable the removal of pollutants such as hydrocarbons and volatile organic compounds (VOCs) by treatment under thermal or catalytical conditions. Combinations of both techniques are also known. VOCs are emissions from various sources (e.g. solvents, reaction products etc. from the paint industry, enaml-ing operations, plywood manufacture, printing industry). They are mostly oxidized catalytically in the presence of Pt, Pd, Fe, Mn, Cu or Cr catalysts. The temperatures in catalytic afterburning processes are much lower than for thermal processes, so avoiding higher NOx levels. The catalysts involved are ceramic or metal honeycombs with washcoats based on cordierite, mullite or perovskites such as LaCoOs or Sr-doped LaCoOs. Conventional catalysts contain Ba-stabilized alumina plus Pt or Pd. 

Toxic volatile organic compounds (VOCs) such as toluene, trichloroethylene, chloroform, and phenol are found in industrial waste waters (including chemistry, pharmacy, electron, petroleum, printing, dope, and textile). Management of industrial waste... 

The science of chemical sensors is being studied at Manchester University for the use and application of conducting polymers [4]. Derivatives of polyaniline, polythiophene, polypyrrole and poly(phenylene vinylene) doped with various ions have been investigated as chemical sensors for biosensors, volatile organic compounds, polymer field-effect gas-sensitive transistors and optical sensors based on electrochromic properties. 

Doped Polymer Light-Emitting Devices and Sensors for Volatile Organic Compounds... 

We are especially interested in reversible sensors for volatile organic compounds (VOCs) in the atmosphere using conducting polymers as the sensing material. The most extensively us conducting polymer to date is polypyrrole (34-38) which is applied in certain commercial sensing instruments (39), Polyanil e, either in its protonated (doped) or non-doped forms, has been studied less extensively (40 45) and polythiophene to an even smaller extent (46-48),... 

Zeng W, Liu T et al (2010) Sensitivity improvement of Ti02-doped Sn02 to volatile organic compounds. Physica E 43(2) 633-638... 

These two are quite different in properties the first is propion-aldehyde, formed by certain bacteria and a reactive, acrid-smelling substance the second is the sweet-smelling acetone, familiar as the volatile base of nail varnish and aeroplane dope. The structure and arrangement in space of the molecules of organic compounds is thus critical to their behaviour. Substances (like proprional-dehyde and acetone) whose overall chemical composition is the same but whose structure and shape are different are called isomers. Isomerism is a common occurrence amongst the chemicals of the living body, and we shall meet it frequently. 

Usually, under heating the destruction of organic compounds to be evaporated occurs on the surface of active alumina sorbents. This phenomenon results in the formation of harmful volatile compounds and the coke that decreases adsorbent capacity. Therefore, it seems more preferable to oxidize organic compounds to carbon dioxide and water during adsorbent regeneration. The processes and purification systems that combine the adsorption and the catalytic combustion regeneration were developed. The transition aluminas doped with catalytic... 

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