Use of siloxane-based polymers or composites in chemical sensor for detecting nitrate compounds

• US 7,749,767 B2
• Filed: 12/03/2004
• Issued: 07/06/2010
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Hairault, Lionel, Lebret, Bruno, Pasquinet, Eric
• Primary Examiner(s): Gakh; Yelena G
• Assistant Examiner(s): WEISZ, DAVID G
• Application Number:
  US10/581,216
• Publication Number:
  US 20070178600A1
• Time in Patent Office: 2,041 Days
• Field of Search: 524/588, 422/82.01, 422/82.02, 422/98, 422/68.1, 422/102
• US Class Current: 436/107
• CPC Class Codes: G01N 2291/0256 Adsorption, desorption, surface mass change, e.g. on biosensors
• CPC Class Codes: G01N 2291/02863 Electric or magnetic parameters
• CPC Class Codes: G01N 2291/0426 Bulk waves, e.g. quartz crystal microbalance, torsional waves
• CPC Class Codes: G01N 27/126 comprising organic polymers
• CPC Class Codes: G01N 29/022 Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices microdevices per se B81B
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 33/0057 Warfare agents or explosives
• CPC Class Codes: Y10T 436/17 Nitrogen containing
• CPC Class Codes: Y10T 436/170769 N-Nitroso containing [e.g., nitrosamine, etc.]

Abstract

The invention relates to the use of at least one polymer comprising a repeating unit of formula (I):

in which:

• • X and Y=single bond or linear C₁-C₅₀ hydrocarbon group;
  • R₁ and R₂=H, CN, C(Z)₃, CH(Z)₂, CH₂Z with Z=halogen; NH₂, NHR₃, NR₃R₄ with R₃, R₄=halogen, CH₃ or linear or branched, saturated or unsaturated C₂-C₂₀ hydrocarbon chain, optionally comprising one or more heteroatoms and/or chemical functions comprising at least one heteroatom; at least one from among R₁ and R₂ being ≠H;
    or of a composite comprising this polymer and one or more conductive charges, as sensitive material in a sensor for detecting nitro compounds.

Applications: Detection of explosives, control/monitoring of atmospheric pollution and of ambient air quality, monitoring of industrial sites.

Claims

1. A method for detecting the presence of at least one nitro compound in a medium, comprising:

contacting said medium with a sensor comprising a substrate having two faces, wherein at least one of the two faces is covered with a sensitive material having at least one physical property which is modified on contact with nitro compounds, wherein said sensitive material is at least one polymer comprising at least one siloxane repeating unit corresponding to the general formula (I) below;

2. The method of claim 1, in which the siloxane repeating unit corresponds to the formula (Id) below:

3. The method of claim 2, in which, in the formula (Id), X represents an alkylene chain containing from 2 to 10 carbon atoms.

4. The method of claim 1, in which the siloxane repeating unit is trifluoropropylmethylsiloxane or cyanopropylmethylsiloxane.

5. The method of claim 1, in which the polymer is chosen in the group consisting of polytrifluoropropylmethylsiloxanes and polycyanopropylmethylsiloxanes.

6. The method of claim 5, in which the polymer has an average molecular weight ranging from 50 to 100 000.

7. The method of claim 1, in which the conductive filler(s) of the composite is(are) chosen in the group consisting of carbon black particles and metal and metal oxide powders.

8. The method of claim 1, in which the polymer or the composite is in the form of a thin film covering one or both faces of the substrate.

9. The method of claim 8, in which the thin film is from 10 angstroms to 100 microns thick.

10. The method of claim 8, in which the thin film is prepared via a technique chosen in the group consisting of spraying, spin coating, drop coating, dip coating, the Langmuir-Blodgett technique, electroplating and in situ polymerization of a precursor monomer of the polymer.

11. The method of claim 1, in which the physical property of the sensitive material which is modified on contact with the nitro compound is the mass of the polymer or the electrical conductivity of the composite.

12. The method of claim 1, in which the sensor is a gravimetric sensor.

13. The method of claim 12, in which the sensor is a quartz microbalance sensor.

14. The method of claim 1, in which the sensor is a resistive sensor.

15. The method of claim 1, in which the nitro compound to be detected is chosen in the group consisting of nitroaromatic compounds, nitroamines, nitrosamines and nitric esters.

16. The method of claim 1, in which the nitro compound to be detected is in solid, liquid or gaseous form.

17. The method of claim 1, in which the nitro compound to be detected is chosen in the group consisting of nitrobenzene, dinitrobenzene, trinitrobenzene, nitrotoluene, dinitrotoluene, trinitrotoluene, dinitrofluorobenzene, dinitrotrifluoromethoxybenzene, aminodinitrotoluene, dinitrotrifluoromethylbenzene, chlorodinitrotrifluoromethylbenzene, hexanitrostilbene, trinitrophenylmethylnitramine and trinitrophenol.

18. The method of claim 1, in which the nitro compound to be detected is a component of explosives.

19. A method for detecting the presence of at least one nitro compound in a medium, comprising:

contacting said medium with a sensor comprising a substrate having two faces, wherein at least one of the two faces is covered with a sensitive material having at least one physical property which is modified on contact with nitro compounds, wherein said sensitive material is at least one polymer comprising at least one siloxane repeating unit corresponding to the formula (Id) below;