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Alginate gels have been explored in relevant domains for daily life such as pharmaceutics and environmental. The structural features of alginate allow functionalization which, in extension, can modify the gel...

Multi-membered O,N,S-heterocycles R 0692 4-(3-(Phtalhydrazide)azo)N-phenylaza-15-crown-5. Synthesis and Properties. -Diazotation of luminol (I) followed coupling of the diazonium salt with azacrown compound (II) provides the title compound (III). In contrast to luminol, (III) is not fluorescent. -(BARATOIU, R. D.; BARBU, A. E.; MUTIHAC, L.; CAPROIU, M. T.; DRAGHICI, C.; SOCOTEANU, R.; CONSTANTINESCU*, T.; Rev. Roum. Chim. 51 (2006) 4, 261-267; Inst. Phys. Chem., Rom. Acad., RO-060021 Bucharest, Rom.; Eng.) -H. Toeppel 52-178

Molecular probes are often used to describe local interactions and to characterize inhomogeneities in complex systems. In this study, two series of monomolecular probes (paramagnetic or fluorescent) and a series of dual molecular probes are used to evaluate local changes and the regions targeted by these probes in three pluronic F127 systems, in the absence and in the presence of 2‐hydroxypropyl‐β‐cyclodextrin, which have been previously characterized. All molecular probes used in this study have as a common structural unit the short oligoethylene chains that link (2,2,6,6‐Tetramethylpiperidin‐1‐yl)oxyl (TEMPO) and/or pyrene moieties. Using these probes, changes in hydrophobicity inside the pluronic micelles are evidenced and the micelle‐to‐gel phase transition is characterized.

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This study aims to analyze the physicochemical properties of solutions containing the mixture of polyacrylates functionalized with alkyl chains moieties and alginate (Alg) functionalized with 𝜷-cyclodextrins (CD). Functionalization of anionic polymers with host (CD) and guest units (alkyl chain) allow local host-guest interaction which determines discrete changes in properties of the resulted mixtures. The systems are investigated by surface tension, viscosity, and zeta-potential measurements, Fourier transform infrared (FTIR), UV-vis, fluorescence, and electron paramagnetic resonance spectroscopies. Spectroscopic methods reveal the local changes induced by the formation of host-guest interactions in modified polyacrylates and modified Alg which explain the macroscopic parameters of solutions such as viscosity, surface tension, and zeta potential. The host-guest interactions stabilize the repulsive forces between the anionic polymers and influence the formation of intercoil of functionalized polyacrylates. The practical application comprises in crystal violet incorporation in the polymeric mixtures and reveals that dyes' properties, such as solubilization and stabilization, may be enhanced. Valuable information, related to the conformational changes generated by the particular formulations of these polymer mixtures, is obtained. The results have the potential applications in chemical sensing, molecular recognition, and the printing industry.