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MID-Infrared Refractive Index Data for Aerosol Particles

The Lorentz Model

The Kramers-Kronig Inversion

The Vibrational Exciton Model

Particle Generation and Characterization

Link to Other Databases

 

Data

        Sugars:

·        deoxyribose, C5H10O4: Lorentz parameters, Kramers-Kronig inversion, estimated uncertainties, experimental conditions
Reference: M. Jetzki and R. Signorell J. Chem. Phys. 2002, 117, 8063-8073. M. Jetzki, Diploma Thesis, University of Goettingen, 2002

·        dihydroxyacetone dimer, C6H12O6: Lorentz parameters , Kramers-Kronig inversion, estimated uncertainties, experimental conditions
Reference: R. Signorell and D. Luckhaus, J. Phys. Chem. A 2002, 106, 4855-4867.

·        erythrose, C4H8O4: Lorentz parameters, Kramers-Kronig inversion, estimated uncertainties, experimental conditions
Reference: M. Jetzki and R. Signorell J. Chem. Phys. 2002, 117, 8063-8073. M. Jetzki, Diploma Thesis, University of Goettingen, 2002

·        fructose, C6H12O6: Lorentz parameters, Kramers-Kronig inversion, estimated uncertainties, experimental conditions
Reference: M. Jetzki and R. Signorell J. Chem. Phys. 2002, 117, 8063-8073. M. Jetzki, Diploma Thesis, University of Goettingen, 2002

·        glucose, C6H12O6: Lorentz parameters, Kramers-Kronig inversion, estimated uncertainties, experimental conditions
Reference: M. Jetzki and R. Signorell J. Chem. Phys. 2002, 117, 8063-8073. M. Jetzki, Diploma Thesis, University of Goettingen, 2002

·        glyceraldehyde dimer, C6H12O6: Lorentz parameters , Kramers-Kronig inversion, estimated uncertainties, experimental conditions
Reference: M. Jetzki and R. Signorell J. Chem. Phys. 2002, 117, 8063-8073. M. Jetzki, Diploma Thesis, University of Goettingen, 2002

·        ribose, C5H10O5: Lorentz parameters , Kramers-Kronig inversion, estimated uncertainties, experimental conditions
Reference: M. Jetzki and R. Signorell J. Chem. Phys. 2002, 117, 8063-8073. M. Jetzki, Diploma Thesis, University of Goettingen, 2002

Queued:

        Polycyclic Aromatic Hydrocarbons:

·        phenantrene, C14H10: Lorentz parameters, estimated uncertainties, experimental conditions
Reference: D. Hermsdorf, A. Bonnamy, M. A. Suhm, and R. Signorell, PCCP 2004, 6, 4652-4657. A. Bonnamy, D. Hermsdorf, R. Ueberschaer, and R. Signorell, Rev. Sci. Instr. 2005, x, y-y

         Organic Acids:

·        formic acid, HCOOH: Lorentz parameters, estimated uncertainties, experimental conditions

·        acetic acid, CH3COOH: Lorentz parameters, estimated uncertainties, experimental conditions

·        formic acid / water: Lorentz parameters, estimated uncertainties, experimental conditions

·        acetic acid / water: Lorentz parameters, estimated uncertainties, experimental conditions

        Drugs:

·        phytosterol

·        ibuprofen

        Molecular Ices:

·        carbondioxide, CO2: Exciton model, conditions
Reference: A. Bonnamy, M. Jetzki, and R. Signorell, Chem. Phys. Lett. 2003, 382, 547-552.

·        12CO2 / 13CO2: Exciton model, conditions
Reference: A. Bonnamy, M. Jetzki, and R. Signorell, Chem. Phys. Lett. 2003, 382, 547-552. R. Signorell and M. K. Kunzmann, Chem. Phys. Lett. 2003, 371, 260-266

·        ammonia, NH3: Exciton model, conditions
Reference: A. Bonnamy, M. Jetzki, and R. Signorell, Chem. Phys. Lett. 2003, 382, 547-552. M. Jetzki, A. Bonnamy and R. Signorell, J. Chem. Phys. 2004, 120, 11775-11784.

·        CO2 / NH3: Exciton model, conditions
Reference: A. Bonnamy, M. Jetzki, and R. Signorell, Chem. Phys. Lett. 2003, 382, 547-552.

·        dinitrogen monoxide, N2O: Exciton model, conditions

·        sulfurdioxide, SO2:Exciton model, conditions

The Lorentz Model

The Lorentz model of matter is a classical theory of optical properties. The molecular oscillators are treated as simple harmonic oscillators which are subject to the driving force of the applied electromagnetic field. A detailed description is given by Bohren and Huffman [1]. The complex dielectric function    is given by:  .

The Lorentz parameters are

·        the resonance wavenumber  of the sth oscillator,

  • the reduced oscillator strength , and
  • the damping constant .

 

The value  represents the contribution of all oscillators well removed to higher frequencies. The Lorentz parameters were obtained by fitting calculated infrared particle spectra to experimental infrared particle spectra. For the calculated infrared particle spectra we have employed Mie-theorie for spherical particles [1].
The parameters n and k of the complex refractive index are linked to the Lorentz parameters of the dielectric function by the following relation:

  • and

and vice versa

  •     and
  • .

 

More information can be found in the following references.

References:

  1. Craig F. Bohren, Donald R. Huffman, Absorption and Scattering of Light by Small Particles, 2nd Ed., Wiley Interscience, New York, 1998.
  2. R. Signorell, D. Luckhaus, J. Phys. Chem. A 2002, 106, 4855-4867.
  3. M. Jetzki, R. Signorell J. Chem. Phys. 2002, 117, 8063-8073.
  4. T. E. Gough and T. Wang, J. Chem. Phys. 1996, 105, 4899-4904.

 

The Kramers-Kronig Inversion

The real ( n ) and imaginary ( k ) part of the complex refractive index   were derived from experimental infrared particle spectra using the Kramers-Kronig inversion and Mie-theory.

A more detailed description of the Kramers-Kronig inversion can be found in the following references.

References:

  1. Craig F. Bohren, Donald R. Huffman, Absorption and Scattering of Light by Small Particles, 2nd Ed., Wiley Interscience, New York, 1998.
  2. R. Signorell, D. Luckhaus, J. Phys. Chem. A 2002, 106, 4855-4867.
  3. R. F. Niedziela, M. L. Norman, C. L. DeForest, R. E. Miller, and D. R. Worsnop, J. Phys. Chem. A 1999, 103, 8030-8040.
  4. M. T. Dohm, A. M. Potscavage, and R. F. Niedziela, J. Phys. Chem. A 2004, 108, 5365-5376.

 

The Vibrational Exciton Model

The real ( n ) and imaginary ( k ) part of the complex refractive index   were derived from calculated infrared particle spectra. These calculated spectra are based on the quantum mechanical vibrational exciton model [1,2]. n  and k  were extracted from these spectra with the help of the Kramers-Kronig inversion or the Lorentz model and Mie-theory [3].

A more detailed description of the vibrational exciton model can be found in the following references.

References:

1.     R. Disselkamp, G. E. Ewing, J. Chem. Phys. 1993, 99, 2439-2448.

2.     R. Signorell, J. Chem. Phys. 2003, 118, 2707-2715.

3.     A. Bonnamy, M. Jetzki, and R. Signorell, Chem. Phys. Lett. 2003, 382, 547-552.

 

Particle Generation and Characterization

Generation in Collisional Cooling Cells [2-8]

Sample: Volatile substances

A warm sample gas is brought to supersaturation by introduction into a cold bath gas. The supersaturation leads to the particle formation.

 

Electrospray Generation [9-11]

Sample: Non-volatile substances

An aqueous solution is sprayed into primary droplets at the tip of a capillary in a high-voltage field. The solvent evaporates from the primary droplets in a sheath flow of dry air. (electrospray)

 

Generation by Rapid Expansion of Supercritical Solutions (RESS) [12-15]

Sample: Non-volatile substances

The RESS-process consists in solvating the substance of interest in a supercritical fluid and in rapidly depressurizing this solution through a small nozzle. The supersonic expansion leads to high supersaturation and consequently to particle formation.

 

Scanning Mobility Particle Sizer (SMPS): Determination of the Number Size Distribution [16]

Sample: Non-volatile substances

The particle sizes are determined by their mobility in an electric field and the number of the particles results from optical counting.

3-Wavelenghts-Extinction Measurements (3-WEM): Determination of the Size Distribution [15,17]

Sample: No restriction

The particle sizes determination is based on extinction measurements of laser light from three different lasers.

 

 

Electron Microscopy: Determination of the Particle Shape and the Number Size Distribution

Sample: Non-volatile substances

Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM)

 

 

 

Detailed descriptions of these techniques can be found in the following references.

References:

  1. William C. Hinds, Aerosol Technology, 2nd Ed., Wiley Interscience, New York, 1998
  2. R. P. Blickensderfer, G. E. Ewing, R. Leonard, Appl. Opt. 1968, 7, 2214-2217
  3. J. A. Barnes, T. E. Gough, M. Stoer, Rev. Sci. Instr. 1989, 60, 406-109.
  4. R. Disselkamp, G. E. Ewing, J. Chem. Phys. 1993,99, 2439-2448.
  5. D. Newnham, J. Ballard, M. Page, Rec. Sci. Instr. 1995, 68, 4475-4481.
  6. M. L. Clapp, R. E. Miller, D. R. Worsnop, J. Phys. Chem. 1995, 99, 6317-6326.
  7. M. K. Kunzmann, R. Signorell, and M. Taraschewski, S. Bauerecker, PCCP. 2001, 3, 3742-3749.
  8. S. Bauerecker, M. Taraschewski, C. Weitkamp, H. K. Cammenga, Rev. Sci. Instr. 2001, 72, 3946
  9. R. Signorell, M. K. Kunzmann, and M. A. Suhm, Chem. Phys. Lett. 2000, 329, 52-60.
  10. M. Jetzki, R. Signorell J. Chem. Phys. 2002, 117, 8063-8073.
  11. R. Signorell and D. Luckhaus, J. Phys. Chem. A 2002, 106, 4855-4867.
  12. J. W. Tom, P. G. Debenedetti, J. Aerosol Sci. 1991, 22, 555-584.
  13. M. Türk, J. Supercrit. Fluids. 1999, 15, 79-89.
  14. D. Hermsdorf, A. Bonnamy, M. A. Suhm, and R. Signorell, PCCP 2004, 6, 4652-4657.
  15. A. Bonnamy, D. Hermsdorf, R. Ueberschaer, and R. Signorell, Rev. Sci. Instr. 2005, x, y-y.
  16. S. L. Kaufman, R. Caldow, F. D. Dorman, K. D. Irwin, A. Pöcher, J. Aerosol Sci. 1999, 30, S373.
  17. J. Meyer, M. Katzer, E. Schmidt, S. Cihlar, and M. Türk, Proceedings of the World Congress on Particle Technology 3, July 6-9, 1998, Brighton, UK, paper 31

 

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