Novel Chemical Sensor Concept for Neutral Radical Detection in Gas Phase

2005 ◽  
Vol 876 ◽  
Author(s):  
Vladislav V. Styrov ◽  
Alex Y. Kabansky ◽  
Victor P. Grankin ◽  
Stanislav Kh. Shigalugov ◽  
Yuri I. Tyurin
Keyword(s):  
Gas Phase ◽  
Chemical Sensor ◽  
Proximate Analysis ◽  
Semiconductor Films ◽  
Neutral Radical ◽  
Enhanced Sensitivity ◽  
Radical Detection ◽  
State Chemical ◽  
Novel Concept ◽  
Heterogeneous Chemical Reactions

AbstractA novel concept of solid-state chemical sensors for neutral radical detection in gas-phase and related technique are proposed based on chemiluminescence of sensing materials excited by heterogeneous chemical reactions of radicals on sensor surface. The radical species of interest include H, O, N, O2, CO, SO, NO and others. Surface activated phosphors, nano-phosphors and semiconductor films are good candidates for sensors. The advantages of these sensors are the enhanced sensitivity (~105at/cm-3or better), real-time response, reliability, proximate analysis, ability to be fabricated in combination with up-to-date nanotechnologies.

scholarly journals Mid-IR evanescent-field fiber sensor with enhanced sensitivity for volatile organic compounds

RSC Advances ◽  
2019 ◽  
Vol 9 (37) ◽  
pp. 21186-21191 ◽  
Author(s):  
Farah Alimagham ◽  
Max Platkov ◽  
Joshua Prestage ◽  
Svetlana Basov ◽  
Gregory Izakson ◽  
...  
Keyword(s):  
Organic Compound ◽  
Gas Phase ◽  
Organic Compounds ◽  
Volatile Organic Compound ◽  
Evanescent Field ◽  
Fiber Sensor ◽  
Porous Coating ◽  
Enhanced Sensitivity ◽  
Volatile Organic ◽  
Increased Sensitivity

Increased sensitivity of mid-IR evanescent field sensing for gas-phase volatile organic compound detection using a nano-porous coating of an optical-fibre.

Ceramic Materials for Mass-Sensitive Sensors - Detection of VOCs and Monitoring Oil Degradation

2006 ◽  
Vol 45 ◽  
pp. 1799-1802 ◽  
Author(s):  
Peter A. Lieberzeit ◽  
Gerd Glanznig ◽  
Anton Leidl ◽  
Franz L. Dickert
Keyword(s):  
Chemical Sensor ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Oil Degradation ◽  
Phase Measurements ◽  
Sensor Applications ◽  
Enhanced Sensitivity ◽  
Wave Oscillator ◽  
Quartz Substrates ◽  
Micro Balance

Inorganic frameworks obtained by the sol-gel route can be templated by a molecular imprinting (MIP) approach to generate functional cavities. Such MIP ceramics show highly appreaciable properties for chemical sensor applications, because they are inherently chemically and thermally robust. In combination with mass-sensitive devices (e.g. quartz crystal micro balance – QCM, surface transverse wave oscillator - STW), they yield highly selective and sensitive chemical sensors. Gas phase measurements with volatile organic compounds (VOCs) e.g. lead to sensitivities below 1 ppm. Sensitivity can be tuned by the sol-gel-precursor: when hydrolysing more bulky alkoxides, this leads to enhanced sensitivity by increasing porosity as a consequence of slower solvent evaporation. By adding products of oxidative oil degradation to the sol-gel mixture, we succeeded in generating sensors for degradation processes in these complex matrices. This allows parallelly monitoring both the chemical state of oil and changes in viscosity. Sensitivity is enhanced according to the Sauerbrey equation by going from 10 MHz QCM transducers to higher frequencies either by etching the quartz substrates and so reducing the resonator thickness or by applying STWs.

Suitable solid state chemical sensor for HCHO determination

2006 ◽  
Vol 27 (4) ◽  
pp. 313 ◽  
Author(s):  
L. Campanella ◽  
M. Battilotti ◽  
R. Dragone ◽  
I. Mevola
Keyword(s):  
Solid State ◽  
Chemical Sensor ◽  
State Chemical

scholarly journals A Novel Concept for In Situ Gas-Phase Laser Raman Spectroscopy for SOFC

2013 ◽  
Vol 57 (1) ◽  
pp. 1339-1348
Author(s):  
G. Schiller ◽  
C. Auer ◽  
Z. Ilhan ◽  
P. Szabo ◽  
H. Ax ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Gas Phase ◽  
Laser Raman Spectroscopy ◽  
Laser Raman ◽  
Novel Concept

THERMIONIC EMISSION FROM FULLERENES

1992 ◽  
Vol 06 (23n24) ◽  
pp. 3881-3891 ◽  
Author(s):  
Gerhard Walder ◽  
Olof Echt
Keyword(s):  
Time Dependence ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Rate Constants ◽  
Size Range ◽  
Thermionic Emission ◽  
Pulsed Laser ◽  
Yag Laser ◽  
Enhanced Sensitivity ◽  
Extraction Field

Fullerenes in the gas phase, excited by a pulsed laser, exhibit thermionic emission. We analyze the time dependence of the ion yield of C n + in a mass spectrometer. By pulsing the extraction field of the ion lens, we are able to observe delayed ions formed as late as 50 µs after excitation by the 2nd, 3rd or 4th harmonic of a Q-switched YAG laser. The enhanced sensitivity of this new technique allows us to detect delayed ions not only from excited C 60 and C 70, but from all other even-sized clusters in the size range 36≤ n ≤70. Our results do not confirm the assertion that thermionic emission from C 60 and C 70 can be characterized by just 2 or 3 distinct rate constants.

scholarly journals A novel concept for in situ gas-phase laser Raman spectroscopy for solid oxide fuel cell research

2012 ◽  
Vol 111 (1) ◽  
pp. 29-38 ◽  
Author(s):  
G. Schiller ◽  
C. Auer ◽  
W. G. Bessler ◽  
C. Christenn ◽  
Z. Ilhan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Phase ◽  
Solid Oxide ◽  
Laser Raman Spectroscopy ◽  
Oxide Fuel ◽  
Laser Raman ◽  
Novel Concept

Changing PL Intensity from GaAs/Al0.3Ga0.7As Heterostructures due to the Chemisorption of SO2: Effects of Heterostructure Geometry

1993 ◽  
Vol 318 ◽  
Author(s):  
J.F. Geisz ◽  
T.F. Kuech ◽  
A.B. Ellis
Keyword(s):  
Chemical Sensor ◽  
Signal To Noise Ratio ◽  
Surface States ◽  
Surface Charges ◽  
Bulk Charge ◽  
Adsorption Of Gases ◽  
State Chemical ◽  
Pl Intensity ◽  
Measurable Change ◽  
Electronic Surface

ABSTRACTChemical adsorption of gases onto semiconductor surfaces results in a change in the density of electronic surface states. The corresponding change in the number of surface charges gives rise to a measurable change in the bulk charge distribution within the semiconductor. This phenomenon forms the basis of a novel solid-state chemical sensor device using the intensity of photoluminescence (PL) as a measurement technique. We have observed changes in the PL intensity from MOVPE-grown GaAs/Al0 3Ga0 7As heterostructures due to the chemisorption of SO2 onto “photowashed” GaAs surfaces. The photowashing technique is believed to reduce the density of preexisting surface states by removing As from the GaAs surface oxide. The PL signal-to-noise ratio and PL sensitivity characteristics of these chemical sensors may be dramatically improved by varying semiconductor structure. We have observed a range of PL enhancements upon exposure to 0.6% SO2 in flowing N2 from heterostructure layers with various thicknesses and doping densities. These results are explained by comparison with a FEM numerical model derived to correlate the relative PL intensity from various heterostructures to the surface charge density.

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