Comparison of molecular weight distributions of polymers determined by dynamic light scattering

Abstract

Several methods for the treatment of experimental data (including 3 different parameter-fitting procedures, histograms, and Provencher's constrained regularization) are considered which allow to obtain molecular weight distributions w ( M ) from quasielastic light scattering measurements. As a result of the introduction of a few improvements to these methods described in the literature, we were able to use more severe criteria for the quality of the distribution functions obtained, based on the mean-square deviation rather than on the coincidence of a few first moments. The quality of five investigated inversion methods was compared on the basis of simulated and experimental data for flexible chain polymers (polystyrene standards) in dilute solution. a) This work was carried out under The Research Project CPBP 01.12 of the Polish Academy of Sciences.0025-1 16)</87/$03.00

Quasielastische Lichtstreuung von gequollenen Siliconnetzwerken

“…vall t gemessen werden [7] : n ( t ) -Zahl der Photoimpulse i m Zeitintervall t bis t + At; Zur Messung von C ( q , t ) sind prinzipiell zwei Verfahren moglich: uberlagert man das Streulicht m i t einer elektromagnetischen Bezugswelle, z. B. d e m Primarstrahl, spricht m a n vom Heterodynverfahren.…”

“…B. d e m Primarstrahl, spricht m a n vom Heterodynverfahren. Die gemessene Autokorrelationsfunktion k a n n durch ausgedriickt werden [7] (A, B -Apparaturkonstanten; S N ( q , t ) -dynamischer Strukturfaktor).…”