### Abstract

According to the Rayleigh-Debye (RG) theory of light scattering, the intensity of forward scattering is proportional to the volume-squared of the scatterers, independent of their shape or orientation. This makes small-angle light scattering (SALS) attractive as a tool for studying the kinetics of flocculation of model latexes, where the conformation of elemental particles in any floe is unknown. In preparation for such a study using a modified version of the apparatus of Lips and Willis (1973), we experimentally determine the limits under which SALS produced by a He-Ne laser can be used for sizing of monodisperse polystyrene latexes. For every particle in the sample volume to experience the same intensity of incident light (i.e. for negligible extinction), the particle concentration must be less than c_{max}, where c_{max}ld^{6}=(1.08 ± 0.09) × 10^{-26} m^{4}, l is the pathlength and d is the particle diameter. For c <c_{max}, the scattering per particle at 2° is proportional to d^{6} provided d is less than 1 μm, which is considerably larger than for scattering at larger angles. We speculate that the scattering by flocs will be proportional to the square of the number of elemental particles in dependent of their conformation provided the floe is also smaller than 1 μm.

Original language | English (US) |
---|---|

Pages (from-to) | 4837-4842 |

Number of pages | 6 |

Journal | Langmuir |

Volume | 13 |

Issue number | 18 |

State | Published - Sep 3 1997 |

### Profile

### ASJC Scopus subject areas

- Colloid and Surface Chemistry
- Physical and Theoretical Chemistry

### Cite this

*Langmuir*,

*13*(18), 4837-4842.

**Small-angle Rayleigh scattering by relatively large latex particles.** / Ofoli, Robert Y.; Prieve, Dennis C.

Research output: Contribution to journal › Article

*Langmuir*, vol 13, no. 18, pp. 4837-4842.

}

TY - JOUR

T1 - Small-angle Rayleigh scattering by relatively large latex particles

AU - Ofoli,Robert Y.

AU - Prieve,Dennis C.

PY - 1997/9/3

Y1 - 1997/9/3

N2 - According to the Rayleigh-Debye (RG) theory of light scattering, the intensity of forward scattering is proportional to the volume-squared of the scatterers, independent of their shape or orientation. This makes small-angle light scattering (SALS) attractive as a tool for studying the kinetics of flocculation of model latexes, where the conformation of elemental particles in any floe is unknown. In preparation for such a study using a modified version of the apparatus of Lips and Willis (1973), we experimentally determine the limits under which SALS produced by a He-Ne laser can be used for sizing of monodisperse polystyrene latexes. For every particle in the sample volume to experience the same intensity of incident light (i.e. for negligible extinction), the particle concentration must be less than cmax, where cmaxld6=(1.08 ± 0.09) × 10-26 m4, l is the pathlength and d is the particle diameter. For c max, the scattering per particle at 2° is proportional to d6 provided d is less than 1 μm, which is considerably larger than for scattering at larger angles. We speculate that the scattering by flocs will be proportional to the square of the number of elemental particles in dependent of their conformation provided the floe is also smaller than 1 μm.

AB - According to the Rayleigh-Debye (RG) theory of light scattering, the intensity of forward scattering is proportional to the volume-squared of the scatterers, independent of their shape or orientation. This makes small-angle light scattering (SALS) attractive as a tool for studying the kinetics of flocculation of model latexes, where the conformation of elemental particles in any floe is unknown. In preparation for such a study using a modified version of the apparatus of Lips and Willis (1973), we experimentally determine the limits under which SALS produced by a He-Ne laser can be used for sizing of monodisperse polystyrene latexes. For every particle in the sample volume to experience the same intensity of incident light (i.e. for negligible extinction), the particle concentration must be less than cmax, where cmaxld6=(1.08 ± 0.09) × 10-26 m4, l is the pathlength and d is the particle diameter. For c max, the scattering per particle at 2° is proportional to d6 provided d is less than 1 μm, which is considerably larger than for scattering at larger angles. We speculate that the scattering by flocs will be proportional to the square of the number of elemental particles in dependent of their conformation provided the floe is also smaller than 1 μm.

UR - http://www.scopus.com/inward/record.url?scp=0031551398&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031551398&partnerID=8YFLogxK

M3 - Article

VL - 13

SP - 4837

EP - 4842

JO - Langmuir

T2 - Langmuir

JF - Langmuir

SN - 0743-7463

IS - 18

ER -