Latex Particle Size Distribution by Dynamic Light Scattering. Computer Evaluation of Two Alternative Calculation Paths

GUGLIOTTA, L.M.; VEGA, J.R.; MEIRA, G.R.

JOURNAL OF COLLOID AND INTERFACE SCIENCE

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2000 vol. 228 p. 14 - 17

0021-9797

Two calculation paths for estimating the particle size distribution(PSD) of a polymer latex from single-angle dynamic light scattering(DLS) measurements are evaluated on the basis of a numerical example.In the more common ?double-step method,? two calculationsteps are applied, with the intermediate estimation of the particlelight intensity distribution (PLID). In the ?single-step method,?the calculation is performed in one operation. From the specificationof several PSDs, a mathematical model is used to produce thesynthetic measurements. An iterative procedure was applied fordetermining the diameter range and the number of PSD points.The inversion operations were carried out using a regularizationtechnique. For narrow distributions with diameters in the range100?1000 nm, the PSD and the PLID are similar in shape, andboth calculation paths produce similar results. For broad PSDs inthe range 100?1000 nm, and for arbitrary PSDs in the range 10?100 nm (i.e., in the Rayleigh region), the single-step method provedpreferable.