The problem of air quality control is relevant at the present time. There are a lot of different devices and methods of air monitoring. The promising devices for air monitoring are automated air monitoring systems functioning in real time regime. The basic part of such system is a chemical gas sensor. Gas sensors can be combined into the arrays or so called multisensory systems to increase their effectiveness. Sensor arrays using semiconductor sensors based on SiO2CuOx, SiO2SnOxCuOy, SnOxZrOy, silver-polyacrylonitrile thin films made at department of chemistry and ecology have been investigated in this work. As a result of sensors signals processing gas recognition technique has been developed. The recognition of ammonia, nitrogen dioxide, chlorine has been made.

Keywords: monitoring, massifs of sensors, semiconductor sensors of gases

  This paper is devoted to development of gas sensors air control. It is shown that copper oxides are the promising materials for high sensitive sensors. The CuOx film material was syntheses by means of citrate sol-gel technique. The sensors fabricated on the basis of CuOx film material were sensitive to ammonia gas in the range of 25-150 ppm. Working temperature was determined as 180 °C. Such sensors can be used for work area air control of industrial enterprises.

Keywords: gas-sensitive element, atmospheric air, sensors, copper oxides

  Stability of sensors on the basis of inorganic oxide materials is one of the primary goals by working out of atmospheric air control devices. In this work long-term stability of a sensor response on the basis of the SiO2SnOxCuOy material to carbon oxide (II) exposure in a range of concentration 1-100 ppm is studied. It is shown that the sensor response differs high stability and reproducibility. Continuous heating within 21 days to working temperature (350°С) influence its value negligibly.

Keywords: stability of a response, sensor, carbon oxide, material of structure of SiO2SnOxCuOy.

  We have investigated electrical and gas sensitive properties of gas sensor based on carbon nanotubes (CNT) and carbon nanotubes modified by metal oxides (such as tin oxide and silicon oxide).  Also we  have find out that modification of  CNT by  metal oxides helps to  improve film`s adhesion to substrate, decrease electrical resistance, recovery time, working temperature , enhance gas sensitivity in comparison with sensitive elements based  only on CNT or metal oxides. Moreover experimental results showed that properties of composite material depend on concentration correlation of solutions. As a result we can get highest sensitivity of sensor element by choosing optimal relation between concentrations of solutions.

Keywords: Сarbon nanotubes, modification, tin oxide, silicon oxide, gas sensor

In the present workwas carried outmodeling of self-assembly of conductive polymer materials for hybridsensor systems for example polyacrylonitrile with silver metallic inclusions. Implementation of modeling was performed by the Wang-Landau and entropic Monte Carlo simulation based on a model with a fixed valence angle. For modeling polymerization process using an algorithm based on the principles of irreversible aggregation of Eden.Methods of quantum chemistry has been investigated and the possibility of obtaining the silver property PAN, as there doxpolymer.

Keywords: Hybrid sensor systems polyconjugated functional conductive polymers, metal-organic polymer composites, the energy of the Hartree-Focksemi conductor gas sensitive materials, mathematical modeling, Monte Carlo, quantum-chemical calculations

  Results of researches of gas sensitive properties of zinc oxide films grown by reactive rf magnetron sputtering was shown. Process parameters, affected on the gas-sensitive ratio, response time, recovery time and the type of electrical conductivity of obtained films were identified. Optimal modes of magnetron sputtering of zinc oxide for implementing gas sensors (RF sputtering Zn target in a gas mixture of oxygen and argon at a concentration of 80% oxygen, a chamber pressure of 0.8 Pa and the magnetron power 100 W) were established. Avarage response time on NO2 gas was 5-15 sec.  The obtained values ​​of the gas-sensitivity were in the range 30-67% for NO2 concentrations from 20 to 100 ppm, CO and CO2 from 50 to 100 ppm and 81-97% for higher gas concentrations from 500 to 1000 ppm.  

Keywords: Nanotechnology, magnetron sputtering, zinc oxide, thin films, gas sensitivity

  Technology of fabricating unheated gas sensors based on polyacrylonitrile (PAN) using different temperature and time modes of a two stages IR-pyrolyze is developed for the remote control of the human condition. Gas-sensing elements based on PAN films and cobalt- and copper-containing PAN films are fabricated. Gas sensitive characteristics of the gained samples to CO, Cl2 and CHCl3 in atmospheric conditions are determined. We have found that gas-sensitivity of the samples depends on the composition of the original film-forming solution and on the process parameters of fabricating the film material. Moreover the samples show sensitivity and selectivity at room temperature. The benefits of this study is that films based on PAN and metal-PAN are the most promising material for electronic engineering including gas sensors for the remote monitoring of the human condition.

Keywords: Nanocomposite materials, gas-sensing layer, metal-containing organic polymers, IR- pyrolyze

  The experimental studies of technological modes of formation of the elements for hybrid microfluidic sensor systems using focused ion beams by nanotechnology complex UHV NANOFAB are performed. The parameters of the focused ion beam to enable the development of microfluidics components are determined. Methods of forming of microfluidics structures on silicon substrate are studied. Parameters of generated elements were studied by scanning electron microscopy and atomic force microscopy. Formed and studied filtration membranes containing holes from 105 to 150 nm in diameter. The results can be used in the formation of nanoscale structures and the development of manufacturing processes microfluidics components for hybrid systems and lab-on-chip.

Keywords: Nanotechnology, focused ion beams, microfluidics, hybrid systems, sensor, lab-on-chip

  In this work the technology of receiving high-sensitivity gas sensors on the basis of zirconium oxide is developed for hybrid sensor systems. Laboratory samples of sensors of gas on the basis of zirconium oxide are made with use sol-gel method. Gas-sensitive characteristics of samples of sensors in relation to nitrogen dioxide are defined: limit of detection and factor of gas sensitivity. The received gas sensors will help to determine approach of an attack of bronchial asthma some hours prior to its beginning by level of an oxide of nitrogen in exhaled air of the person.

Keywords: hybrid sensor systems, zirconium oxide, bronchial asthma, nitrogen dioxide

Information about authors of issue №2 (2008)

Keywords: authors