%0 Journal Article
%A Michels, Rolf
%A Goerigk, Günter
%A Vainio, Ulla
%A Gummel, Jérémie
%A Huber, Klaus
%T Coaggregation of Two Anionic Azo Dyestuffs: A Combined Static Light Scattering and Small-Angle X-ray Scattering Study
%J The journal of physical chemistry  / B
%V 118
%N 27
%@ 1520-6106
%C Washington, DC
%I Soc.
%M DESY-2014-03392
%P 7618 - 7629
%D 2014
%X The formation of azo dyestuff aggregates in dilute aqueous solution induced by the addition of Mg2+, Ca2+, Sr2+, or Ba2+ ions is followed by time-resolved static light scattering (SLS) and time-resolved small-angle X-ray scattering (SAXS). Time-dependent molar mass data of the growing aggregates is interpreted by means of a kinetic model introduced by Lomakin et al. ( Proc. Natl. Acad. Sci. U.S.A. 1996, 93, 1125) for the description of β-amyloid aggregation. This interpretation reveals significant trends within the homologous series of alkaline earth cations. The trends refer to the nucleation and the growth rate of the dyestuff fibers. Time-resolved SAXS experiments indicate that these first two stages are followed by a third one during which a network forms by partial lateral alignment of fibers. At high enough dyestuff concentrations, this network formation even leads to a gel-like phase. Anomalous SAXS (ASAXS) on such a gel phase formed upon the addition of Sr2+ revealed the extent of neutralization of the dyestuff molecules within the gel by the specifically interacting alkaline earth cations.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000338981200016
%$ pmid:24937796
%R 10.1021/jp502347b
%U https://bib-pubdb1.desy.de/record/171851