Abstract

Fly ash samples from two different generating plants have been examined by laser light scattering techniques. Individual particles below ~3-μm diam, found to be primarily spherical, were electrostatically levitated in a single-particle light scattering photometer while their differential light scattering (DLS) patterns were recorded. During this measurement period, the relative humidity within the scattering cell could be varied to study the water accretion properties of the suspended particle. The recorded DLS patterns are used to derive the complex refractive index, size, and accreted layer thickness of the particle. Each particle appears to have a different refractive index, probably indicative of the varied microscopic conditions of formation. Even at very high relative humidities, the fly ash particle surface does not appear to have a natural affinity for water, contrary to popular expectations.

© 1980 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. D. A. Lundgren, D. W. Cooper, APCA J. 19, 243 (1969).
  2. D. S. Covert, R. J. Charlson, N. C. Ahlquist, J. Appl. Meteorol. 11, 968 (1972).
    [CrossRef]
  3. I. N. Tang, J. Aerosol Sci. 7, 361 (1976).
    [CrossRef]
  4. I. N. Tang, H. R. Munkelwitz, J. G. Davis, Brookhaven National Laboratory Report BNL 2132 (1976).
  5. I. N. Tang, H. R. Munkelwitz, J. G. Davis, J. Aerosol Sci. 8, 149 (1977).
    [CrossRef]
  6. P. J. Wyatt, D. T. Phillips, R. M. Berkman, J. Colloid Interface Sci. 34, 59 (1970).
  7. P. J. Wyatt, J. Colloid Interface Sci. 39, 125 (1972).
    [CrossRef]
  8. K. Takahashi, M. Kasabara, M. Itoh, J. Aerosol Sci. 6, 45 (1975).
    [CrossRef]
  9. S. Martin, in Humidity and Moisture, Vol. 3, A. Wexler, Ed. (Reinhold, New York, 1965), Chap. 29.
  10. “Constant Humidity Solutions,” in Merck Index, P. G. Stecher, Ed. (Merck and Co., Rahway, N.J., 1976), p. MISC-71.
  11. G. L. Fisher, D. P. Y. Chang, M. Brummer, Science 192, 553 (1976).
    [CrossRef] [PubMed]
  12. P. J. Wyatt, Ed. Atlas of Light Scattering Curves (Science Spectrum, Inc., Santa Barbara, Calif., 1977).
  13. P. J. Wyatt, in Methods in Microbiology, J. R. Norris, D. W. Ribbons, Eds. (Academic, New York, 1973), Chap. 6.
  14. M. Kerker, The Scattering of Light and Other Electromagnetic Radiation (Academic, New York, 1969).
  15. A. L. Aden, M. Kerker, J. Appl. Phys. 22, 1242 (1951).
    [CrossRef]
  16. P. J. Wyatt, D. T. Phillips, J. Theor. Biol. 37, 493 (1972).
    [CrossRef] [PubMed]
  17. P. J. Wyatt, J. Appl. Bacteriol. 38, 47 (1975).
    [CrossRef] [PubMed]
  18. See P. R. Bevington, Data Reduction and Error Analysis for the Physical Sciences (McGraw-Hill, New York, 1969).
  19. L. D. Faddeyev, J. Math. Phys. N.Y. 4, 72 (1963).
    [CrossRef]
  20. J. Shmoys, J. Appl. Phys. 32, 689 (1961).
    [CrossRef]
  21. R. Mireles, J. Math. Phys. N.Y. 45, 179 (1966).
  22. R. G. Newton, J. Math. Phys. 3, 75 (1962).
    [CrossRef]
  23. D. D. Cooke, M. Kerker, J. Colloid Interface Sci. 42, 1 (1973).
    [CrossRef]
  24. D. T. Phillips, P. J. Wyatt, Appl. Opt. 11, 2082 (1972).
    [CrossRef] [PubMed]

1977 (1)

I. N. Tang, H. R. Munkelwitz, J. G. Davis, J. Aerosol Sci. 8, 149 (1977).
[CrossRef]

1976 (2)

I. N. Tang, J. Aerosol Sci. 7, 361 (1976).
[CrossRef]

G. L. Fisher, D. P. Y. Chang, M. Brummer, Science 192, 553 (1976).
[CrossRef] [PubMed]

1975 (2)

K. Takahashi, M. Kasabara, M. Itoh, J. Aerosol Sci. 6, 45 (1975).
[CrossRef]

P. J. Wyatt, J. Appl. Bacteriol. 38, 47 (1975).
[CrossRef] [PubMed]

1973 (1)

D. D. Cooke, M. Kerker, J. Colloid Interface Sci. 42, 1 (1973).
[CrossRef]

1972 (4)

D. T. Phillips, P. J. Wyatt, Appl. Opt. 11, 2082 (1972).
[CrossRef] [PubMed]

P. J. Wyatt, D. T. Phillips, J. Theor. Biol. 37, 493 (1972).
[CrossRef] [PubMed]

P. J. Wyatt, J. Colloid Interface Sci. 39, 125 (1972).
[CrossRef]

D. S. Covert, R. J. Charlson, N. C. Ahlquist, J. Appl. Meteorol. 11, 968 (1972).
[CrossRef]

1970 (1)

P. J. Wyatt, D. T. Phillips, R. M. Berkman, J. Colloid Interface Sci. 34, 59 (1970).

1969 (1)

D. A. Lundgren, D. W. Cooper, APCA J. 19, 243 (1969).

1966 (1)

R. Mireles, J. Math. Phys. N.Y. 45, 179 (1966).

1963 (1)

L. D. Faddeyev, J. Math. Phys. N.Y. 4, 72 (1963).
[CrossRef]

1962 (1)

R. G. Newton, J. Math. Phys. 3, 75 (1962).
[CrossRef]

1961 (1)

J. Shmoys, J. Appl. Phys. 32, 689 (1961).
[CrossRef]

1951 (1)

A. L. Aden, M. Kerker, J. Appl. Phys. 22, 1242 (1951).
[CrossRef]

Aden, A. L.

A. L. Aden, M. Kerker, J. Appl. Phys. 22, 1242 (1951).
[CrossRef]

Ahlquist, N. C.

D. S. Covert, R. J. Charlson, N. C. Ahlquist, J. Appl. Meteorol. 11, 968 (1972).
[CrossRef]

Berkman, R. M.

P. J. Wyatt, D. T. Phillips, R. M. Berkman, J. Colloid Interface Sci. 34, 59 (1970).

Bevington, P. R.

See P. R. Bevington, Data Reduction and Error Analysis for the Physical Sciences (McGraw-Hill, New York, 1969).

Brummer, M.

G. L. Fisher, D. P. Y. Chang, M. Brummer, Science 192, 553 (1976).
[CrossRef] [PubMed]

Chang, D. P. Y.

G. L. Fisher, D. P. Y. Chang, M. Brummer, Science 192, 553 (1976).
[CrossRef] [PubMed]

Charlson, R. J.

D. S. Covert, R. J. Charlson, N. C. Ahlquist, J. Appl. Meteorol. 11, 968 (1972).
[CrossRef]

Cooke, D. D.

D. D. Cooke, M. Kerker, J. Colloid Interface Sci. 42, 1 (1973).
[CrossRef]

Cooper, D. W.

D. A. Lundgren, D. W. Cooper, APCA J. 19, 243 (1969).

Covert, D. S.

D. S. Covert, R. J. Charlson, N. C. Ahlquist, J. Appl. Meteorol. 11, 968 (1972).
[CrossRef]

Davis, J. G.

I. N. Tang, H. R. Munkelwitz, J. G. Davis, J. Aerosol Sci. 8, 149 (1977).
[CrossRef]

I. N. Tang, H. R. Munkelwitz, J. G. Davis, Brookhaven National Laboratory Report BNL 2132 (1976).

Faddeyev, L. D.

L. D. Faddeyev, J. Math. Phys. N.Y. 4, 72 (1963).
[CrossRef]

Fisher, G. L.

G. L. Fisher, D. P. Y. Chang, M. Brummer, Science 192, 553 (1976).
[CrossRef] [PubMed]

Itoh, M.

K. Takahashi, M. Kasabara, M. Itoh, J. Aerosol Sci. 6, 45 (1975).
[CrossRef]

Kasabara, M.

K. Takahashi, M. Kasabara, M. Itoh, J. Aerosol Sci. 6, 45 (1975).
[CrossRef]

Kerker, M.

D. D. Cooke, M. Kerker, J. Colloid Interface Sci. 42, 1 (1973).
[CrossRef]

A. L. Aden, M. Kerker, J. Appl. Phys. 22, 1242 (1951).
[CrossRef]

M. Kerker, The Scattering of Light and Other Electromagnetic Radiation (Academic, New York, 1969).

Lundgren, D. A.

D. A. Lundgren, D. W. Cooper, APCA J. 19, 243 (1969).

Martin, S.

S. Martin, in Humidity and Moisture, Vol. 3, A. Wexler, Ed. (Reinhold, New York, 1965), Chap. 29.

Mireles, R.

R. Mireles, J. Math. Phys. N.Y. 45, 179 (1966).

Munkelwitz, H. R.

I. N. Tang, H. R. Munkelwitz, J. G. Davis, J. Aerosol Sci. 8, 149 (1977).
[CrossRef]

I. N. Tang, H. R. Munkelwitz, J. G. Davis, Brookhaven National Laboratory Report BNL 2132 (1976).

Newton, R. G.

R. G. Newton, J. Math. Phys. 3, 75 (1962).
[CrossRef]

Phillips, D. T.

D. T. Phillips, P. J. Wyatt, Appl. Opt. 11, 2082 (1972).
[CrossRef] [PubMed]

P. J. Wyatt, D. T. Phillips, J. Theor. Biol. 37, 493 (1972).
[CrossRef] [PubMed]

P. J. Wyatt, D. T. Phillips, R. M. Berkman, J. Colloid Interface Sci. 34, 59 (1970).

Shmoys, J.

J. Shmoys, J. Appl. Phys. 32, 689 (1961).
[CrossRef]

Takahashi, K.

K. Takahashi, M. Kasabara, M. Itoh, J. Aerosol Sci. 6, 45 (1975).
[CrossRef]

Tang, I. N.

I. N. Tang, H. R. Munkelwitz, J. G. Davis, J. Aerosol Sci. 8, 149 (1977).
[CrossRef]

I. N. Tang, J. Aerosol Sci. 7, 361 (1976).
[CrossRef]

I. N. Tang, H. R. Munkelwitz, J. G. Davis, Brookhaven National Laboratory Report BNL 2132 (1976).

Wyatt, P. J.

P. J. Wyatt, J. Appl. Bacteriol. 38, 47 (1975).
[CrossRef] [PubMed]

P. J. Wyatt, D. T. Phillips, J. Theor. Biol. 37, 493 (1972).
[CrossRef] [PubMed]

D. T. Phillips, P. J. Wyatt, Appl. Opt. 11, 2082 (1972).
[CrossRef] [PubMed]

P. J. Wyatt, J. Colloid Interface Sci. 39, 125 (1972).
[CrossRef]

P. J. Wyatt, D. T. Phillips, R. M. Berkman, J. Colloid Interface Sci. 34, 59 (1970).

P. J. Wyatt, in Methods in Microbiology, J. R. Norris, D. W. Ribbons, Eds. (Academic, New York, 1973), Chap. 6.

APCA J. (1)

D. A. Lundgren, D. W. Cooper, APCA J. 19, 243 (1969).

Appl. Opt. (1)

J. Aerosol Sci. (3)

I. N. Tang, J. Aerosol Sci. 7, 361 (1976).
[CrossRef]

I. N. Tang, H. R. Munkelwitz, J. G. Davis, J. Aerosol Sci. 8, 149 (1977).
[CrossRef]

K. Takahashi, M. Kasabara, M. Itoh, J. Aerosol Sci. 6, 45 (1975).
[CrossRef]

J. Appl. Bacteriol. (1)

P. J. Wyatt, J. Appl. Bacteriol. 38, 47 (1975).
[CrossRef] [PubMed]

J. Appl. Meteorol. (1)

D. S. Covert, R. J. Charlson, N. C. Ahlquist, J. Appl. Meteorol. 11, 968 (1972).
[CrossRef]

J. Appl. Phys. (2)

A. L. Aden, M. Kerker, J. Appl. Phys. 22, 1242 (1951).
[CrossRef]

J. Shmoys, J. Appl. Phys. 32, 689 (1961).
[CrossRef]

J. Colloid Interface Sci. (3)

D. D. Cooke, M. Kerker, J. Colloid Interface Sci. 42, 1 (1973).
[CrossRef]

P. J. Wyatt, D. T. Phillips, R. M. Berkman, J. Colloid Interface Sci. 34, 59 (1970).

P. J. Wyatt, J. Colloid Interface Sci. 39, 125 (1972).
[CrossRef]

J. Math. Phys. (1)

R. G. Newton, J. Math. Phys. 3, 75 (1962).
[CrossRef]

J. Math. Phys. N.Y. (2)

L. D. Faddeyev, J. Math. Phys. N.Y. 4, 72 (1963).
[CrossRef]

R. Mireles, J. Math. Phys. N.Y. 45, 179 (1966).

J. Theor. Biol. (1)

P. J. Wyatt, D. T. Phillips, J. Theor. Biol. 37, 493 (1972).
[CrossRef] [PubMed]

Science (1)

G. L. Fisher, D. P. Y. Chang, M. Brummer, Science 192, 553 (1976).
[CrossRef] [PubMed]

Other (7)

P. J. Wyatt, Ed. Atlas of Light Scattering Curves (Science Spectrum, Inc., Santa Barbara, Calif., 1977).

P. J. Wyatt, in Methods in Microbiology, J. R. Norris, D. W. Ribbons, Eds. (Academic, New York, 1973), Chap. 6.

M. Kerker, The Scattering of Light and Other Electromagnetic Radiation (Academic, New York, 1969).

See P. R. Bevington, Data Reduction and Error Analysis for the Physical Sciences (McGraw-Hill, New York, 1969).

S. Martin, in Humidity and Moisture, Vol. 3, A. Wexler, Ed. (Reinhold, New York, 1965), Chap. 29.

“Constant Humidity Solutions,” in Merck Index, P. G. Stecher, Ed. (Merck and Co., Rahway, N.J., 1976), p. MISC-71.

I. N. Tang, H. R. Munkelwitz, J. G. Davis, Brookhaven National Laboratory Report BNL 2132 (1976).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)

Fig. 1
Fig. 1

Unretouched photograph of a single 1200-nm diam latex particle (arrow). The 5-mW vertically polarized He–Ne laser beam is incident from the left, and a Rayleigh horn light trap is seen at the right.

Fig. 2
Fig. 2

DLS pattern from an irregular fly ash particle.

Fig. 3
Fig. 3

DLS pattern from a homogeneous fly ash particle (ID 19052). Two traces. Best-fit parameters: R = 1280 ± 2 nm, n1 = 1.515 ± 0.01, n2 = 0.008 ± 0.002 (see Fig. 9).

Fig. 4
Fig. 4

DLS pattern from a homogeneous fly ash particle (ID 1603). Single trace. Best-fit parameters: R = 563 ± 2 nm, n1 = 1.555 ± 0.01, n2 = 0.005 ± 0.002 (see Fig. 10).

Fig. 5
Fig. 5

DLS pattern from a homogeneous fly ash particle (ID 19051). Two traces. Best-fit parameters: R = 590 ± 2 nm, n1 = 1.56 ± 0.01, n2 = 0.0 (see Fig. 11).

Fig. 6
Fig. 6

DLS patterns from a NaCl particle inserted into a high relative humidity (98%) atmosphere showing variations and growth with time. Single traces. (A) Ambient humidity; (B) 98% relative humidity at 1 min; (C) 98% relative humidity at 3 min.

Fig. 7
Fig. 7

DLS patterns from a homogeneous fly ash particle (ID 604) at (A) 20% relative humidity and (B) 98% relative humidity. Two traces for each case. Best-fit parameters: (A) R = 1152 ± 2 nm, n1 = 1.54 ± 0.01, n2 = 0.003 ± 0.001; (B) Rcoat = 1161.5 ± 2 nm, ncoat = 1.33 ± 0.01 (see Fig. 12).

Fig. 8
Fig. 8

DLS patterns from a homogeneous fly ash particle (ID 903) at (A) 20% relative humidity and (B) 98% relative humidity. Single traces. Best-fit parameters: (A) R = 838 ± 2 nm, n1 = 1.49 ± 0.01, n2 = 0; (B) Rcoat = 841 ± 1 nm, ncoat = 1.35 ± 0.03 (see Fig. 13).

Fig. 9
Fig. 9

Theoretical best-fit to the data of Fig. 3.

Fig. 10
Fig. 10

Theoretical best-fit to the data of Fig. 4.

Fig. 11
Fig. 11

Theoretical best-fit to the data of Fig. 5.

Fig. 12
Fig. 12

Theoretical best-fit to the data of Fig. 7.

Fig. 13
Fig. 13

Theoretical best-fit to the data of Fig. 8.

Tables (3)

Tables Icon

Table I Selected Q-Values for Particle 19051 (Utah)a

Tables Icon

Table II Selected Q-Values for Particle 19052 (Utah)a

Tables Icon

Table III Selected Q-Values for Particle 604 (Four Corners) at 98% RHa

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

Q = 1 N i = 1 N ( I i T - α I i E ) 2 ,
α = i I i E 2 / i I i T I i E .
s 2 = 1 N - n - 1 i 1 σ i 2 ( α I i E - I i T ) 2 , 1 N i 1 σ i 2 ,

Metrics