Assessment of S(0,phi) from multiply scattered light

Two-wavelength measurements of isotropic scattering coefficient in concentr ated, multiply scattering colloidal suspensions are used to extract S(0,phi ) values, using a small wave number expansion of the interparticle structur e factor, S(q,phi). Owing to the small particle size (150 nm) and near-infr ared wavelengths (670-820 nm) used in this study, the approximation is reas onable and allows accurate estimation of S(0,phi). The estimated values of S(0,phi) agree well with that predicted using the Carnahan-Starling equatio n of state. (C) 1999 American Institute of Physics. [S0021- 9606(99)52044-8 ].