Polyelectrolyte complexes. V. Solid‐state properties of some polycation/azo dye complexes controlled by the dye structure

Abstract

The solid-state properties of some polycation/azo dye complexes according to the dye structure were studied in this work. One polycation contained about 95 mol % N,N-dimethyl-2-hydroxypropyleneammonium chloride units in the backbone (PCA 5 ), and eight azo dyes, different in either the number of sulfonic groups or their distribution, were used as opposite components. The selected azo dyes were as Crystal Scarlet, Congo Red, Crocein Scarlet MOO, Ponceau SS, Amaranth, Ponceau S, Direct Blue 1, and Direct Red 80. Information on the compensation degree of the oppositely charges was obtained by the elemental analysis of the solid-state polycation/dye complexes (the experimental contents of chlorine, nitrogen, and sulfur were compared with the calculated values). Differential scanning calorimetry was employed to probe the strength of the intermolecular interactions in the PCA 5 /dye complexes. Wide-angle X-ray diffraction was used to assess the supramolecular order of the solid-state complexes. The physical properties of the PCA 5 /azo dye complexes (the complex stoichiometry, glasstransition temperature, decomposition temperature, and degree of supramolecular order) were influenced mainly by the dye structure but also by the polycation concentration and the presence of NaCl.

Interaction of dis‐azo dyes with quaternized poly(dimethylaminoethyl methacrylate) as a function of the dye structure and polycation charge density

“…In our previous investigations, PCs containing quaternary ammonium groups in the backbone were synthesized19, 20 and used in the separation of montmorillonite21 and in dye removal 22. The stoichiometry of PC/azo dye complexes23–25 and the formation of PC/dye/polyanion tricomponent complexes26 have been also investigated. In this study, we focused on the interactions of some dis‐azo dyes, different by either the position of sulfonic groups, with two isomers being selected [Ponceau SS (PSS) and Crocein Scarlet MOO (CSMOO)], or the number of anionic groups, with two benzidine‐type azo dyes being used [Congo Red (CR) and Direct Blue 1 (DB1)], with some PCs, having cationic centers in the side chain.…”

Thermochemically induced binding of methyl orange to polycations containing primary amine groups

“…Molecular systems incorporating azobenzene chromophores continue to be a fascinating area of investigation attracting growing interest in both academia and practice 1, 2. Azobenzene groups can be part of a cationic or anionic bipolar amphiphile,3, 4 a polymer with azobenzene in the side chains5–15 or in the backbone,16–19 block copolymers,20–22 azo dyes and their complexes with polycations (PCs) in solid state and solution23–26 or in multilayer thin films,27–39 and so forth. The azobenzene moieties, present in photoresponsive systems, photoisomerize from the thermodynamically more stable trans configuration (E‐form) to the cis form (Z‐form) by UV‐light irradiation.…”