scholarly journals Effect of Thermal Treatments on the Transduction Behaviors of Conductometric Hydrogen Gas Sensors Integrated with HCl-Doped Polyaniline Nanofibers

2007 ◽  
Vol 1042 ◽  
Author(s):  
Pen-Cheng Wang ◽  
Yaping Dan ◽  
Luke A. Somers ◽  
Alan G. MacDiarmid ◽  
A.T. Charlie Johnson
Keyword(s):  
Thermal Treatment ◽  
Electrical Resistance ◽  
Adsorbed Water ◽  
Opposite Polarity ◽  
Hydrogen Gas ◽  
Thermal Treatments ◽  
Polyaniline Nanofibers ◽  
Pani Nanofibers ◽  
Hydrogen Gas Sensors ◽  
Doped Polyaniline

AbstractWe present the effect of thermal treatments on the transduction behaviors of HCl-doped polyaniline (PANI) nanofibers integrated in conductometric devices upon exposure to 1% H2 (carried by N2). After drying in N2 at 25ºC for 12 hours, devices showed a ∼10% decrease in electrical resistance upon exposure to 1% H2. However, devices subject to 12-hour drying in N2 at 25ºC followed by further thermal treatments in N2 at 100ºC, 164ºC or 200ºC for 30 minutes showed different transduction behaviors. Specifically, devices subject to thermal treatments at 100ºC and 164ºC showed a decrease in electrical resistance by ∼7% and <0.5%, respectively. More interestingly, the device subject to thermal treatment at 200ºC showed a transduction behavior with opposite polarity, i.e. a ∼5% increase in electrical resistance upon exposure to 1% H2. SEM, FTIR and TGA were employed to investigate the effect of thermal treatments on the morphology and chemical characteristics of HCl-doped polyaniline nanofibers. The results indicated that the change in the devices' interesting transduction behaviors might be related to the thermal treatment effects on the HCl-doped PANI nanofibers in (i) removal of adsorbed water, and (ii) crosslinking and/or degradation of polymer backbones.

scholarly journals A multilevel investigation supported by multivariate analysis for tomato product formulation

2021 ◽  
Author(s):  
Fatma Boukid ◽  
Elena Curti ◽  
Agoura Diantom ◽  
Eleonora Carini ◽  
Elena Vittadini
Keyword(s):  
Thermal Treatment ◽  
Color Change ◽  
Water Molecules ◽  
Thermal Treatments ◽  
Industrial Processing ◽  
H Nmr ◽  
Mobile Populations ◽  
Product Formulation ◽  
Tomato Product ◽  
The Impact

AbstractIndustrial processing of tomato includes its cutting and mincing, thermal treatments, and the addition of ingredients, which might induce changes in physicochemical properties of the final products. In this frame, the impact of texturing/thickening [xanthan gum (X) or potato fiber (F)] on the macroscopic, mesoscopic and molecular properties of tomato double concentrate (TDC) was investigated to determine if F can efficiently substitute X, in association with small solutes (sugar and salt) and thermal treatment (cold and hot). At a macroscopic level, multivariate statistics (MANOVA) underlined that color change (ΔE) was increased by X and F addition contrary to heating and the addition of salt and sugar. MANOVA revealed that texture was greatly enhanced through the use of F over X. 1H NMR molecular mobility changes were more controlled by texturing agents (F and X) than thermal treatment and small solutes. Particularly F increased the more rigid population indicating stronger interaction with water molecules resulting in shear-thinning flow. However, adding X contributed into the increase of the dynamic and mobile populations. Therefore, F can be a valid “clean label” substitute of X in modulating tomato products properties.

Pt/GaN Schottky diodes for hydrogen gas sensors

2006 ◽  
Vol 113 (2) ◽  
pp. 797-804 ◽  
Author(s):  
M. Ali ◽  
V. Cimalla ◽  
V. Lebedev ◽  
H. Romanus ◽  
V. Tilak ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Schottky Diodes ◽  
Hydrogen Gas ◽  
Hydrogen Gas Sensors

Unusual morphologies of reduced graphene oxide and polyaniline nanofibers-reduced graphene oxide composites for high performance supercapacitor applications

RSC Advances ◽  
2014 ◽  
Vol 4 (43) ◽  
pp. 22551-22560 ◽  
Author(s):  
Rahul S. Diggikar ◽  
Dattatray J. Late ◽  
Bharat B. Kale
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Performance ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Polyaniline Nanofibers ◽  
Pani Nanofibers ◽  
Reduced Graphene ◽  
Oxide Composites ◽  
Enhanced Electrochemical Performance ◽  
Supercapacitor Applications

The unique morphologies of reduced graphene oxide (RGO) and RGO–PANI nanofibers (NF) composites have been demonstrated. The enhanced electrochemical performance was observed for honeycomb like RGO–PANI NFs composites.

scholarly journals Hydrogen Gas Sensors Fabricated on Atomically Flat 4H-SiC Webbed Cantilevers

2008 ◽  
Vol 600-603 ◽  
pp. 1199-1202 ◽  
Author(s):  
Philip G. Neudeck ◽  
David J. Spry ◽  
Andrew J. Trunek ◽  
Laura J. Evans ◽  
Liang Yu Chen ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Rapid Detection ◽  
Hydrogen Gas ◽  
Current Gain ◽  
Proper Selection ◽  
Hydrogen Gas Sensors ◽  
Sensor Current ◽  
Atomically Flat ◽  
Initial Results ◽  
Selection Of

This paper reports on initial results from the first device tested of a “second generation” Pt-SiC Schottky diode hydrogen gas sensor that: 1) resides on the top of atomically flat 4H-SiC webbed cantilevers, 2) has integrated heater resistor, and 3) is bonded and packaged. With proper selection of heater resistor and sensor diode biases, rapid detection of H2 down to concentrations of 20 ppm was achieved. A stable sensor current gain of 125 ± 11 standard deviation was demonstrated during 250 hours of cyclic test exposures to 0.5% H2 and N2/air.

XXXVII.—On a Sensitive State induced in Magnetic Materials by Thermal Treatment.

1908 ◽  
Vol 28 ◽  
pp. 615-626
Author(s):  
James G. Gray ◽  
Alexander D. Ross
Keyword(s):  
Thermal Treatment ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Temperature Scale ◽  
Steel Wire ◽  
Steady Temperature ◽  
Appreciable Change ◽  
Fatigue Effect ◽  
Stone Slab ◽  
Equal Temperature

SUMMARY1. Nickel and the Heusler alloy give “sensitive states” of nearly 2 and about 5 per cent. respectively for a magnetising field of 8 C.G.S. units.2. Steel wire specimens dropped vertically on a stone slab from a height of 1 metre showed a reduction of 37 per cent, in the “sensitive state” for a single fall, 49 per cent, for three falls, 62 per cent, for ten falls, and 73 per cent, for fifty falls.3. After the “sensitive state” has been removed from a specimen by the process of demagnetising by reversals, it cannot be completely restored by reannealing. That is, the specimens exhibit a fatigue effect.4. In the case of one variety of steel, the “sensitive state” had been reduced to less than one-half its original value after seven annealings, and to one-fifth after seventeen.5. No recovery from the fatigue condition was observed in specimens which had been laid aside for fifty-four days.6. Repeated annealings without intermediate magnetic testing showed neither an augmentation of the “sensitive state” nor a fatigue effect.7. Specimens demagnetised at −190° C., heated to room temperature, and cooled again to −190° C., showed a small “sensitive state” at that temperature.8. Larger effects were induced by heating from −190° C. to 15° C., or by cooling from 15° C. to −190° C.9. A “sensitive state” could be induced by any variation of temperature, but not by exposure to a steady temperature, either high or low. The effect is associated solely with change of temperature.10. The amount of “sensitive state” induced by equal temperature alterations varies with the position of the range on the temperature scale and with the material.11. The change from the “sensitive” to the normal condition is unaccompanied by any appreciable change in the specific electrical resistance or elastic constants of the material.

High performance and negative temperature coefficient of low temperature hydrogen gas sensors using palladium decorated tungsten oxide

2015 ◽  
Vol 3 (3) ◽  
pp. 1317-1324 ◽  
Author(s):  
Yanrong Wang ◽  
Bin Liu ◽  
Songhua Xiao ◽  
Han Li ◽  
Lingling Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Coefficient ◽  
Gas Sensors ◽  
High Performance ◽  
Negative Temperature Coefficient ◽  
Solvothermal Method ◽  
Negative Temperature ◽  
Hydrogen Sensor ◽  
Hydrogen Gas ◽  
Hydrogen Gas Sensors

A catalytically activated hydrogen sensor is obtained based on Pd decorated WO3 nanoplates constructed by a solvothermal method.

scholarly journals Titanium Dioxide-Based64∘YXLiNbO3Surface Acoustic Wave Hydrogen Gas Sensors

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
A. Z. Sadek ◽  
D. Buso ◽  
A. Martucci ◽  
P. Mulvaney ◽  
W. Wlodarski ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Acoustic Wave ◽  
Gas Sensors ◽  
Sol Gel ◽  
Hydrogen Gas ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Helium Atmosphere ◽  
Gas Detectors ◽  
Hydrogen Gas Sensors

Amorphous titanium dioxide (TiO2) and gold (Au) dopedTiO2-based surface acoustic wave (SAW) sensors have been investigated as hydrogen gas detectors. The nanocrystal-dopedTiO2films were synthesized through a sol-gel route, mixing a Ti-butoxide-based solution with diluted colloidal gold nanoparticles. The films were deposited via spin coating onto64∘YXLiNbO3SAW transducers in a helium atmosphere. The SAW gas sensors were operated at various temperatures between 150 and310∘C. It was found that gold doping onTiO2increased the device sensitivity and reduced the optimum operating temperature.

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