We investigated physicochemical characteristics of dye lots sold as "alcian blue" using the Biological Stain Commission (BSC) precipitation test, differential scanning calorimetry, high performance liquid chromatography, thin layer chromatography and UV/visible spectroscopy. Four blue phthalocyanine dyes were detected in 11 commercial dye lots. These four included the original ingrain blue 1 CI 74000 dye and the dye sold with the name "alcian blue pyridine variant"; we discuss also the possible identity of the additional two dyes.
View Article and Find Full Text PDFOxidative stress caused by free radicals is one of the great threats to inflict intracellular damage. Here, we report a convenient approach to the synthesis, characterization, and evaluation of the radical activity of titanium-based composites. We have investigated the potential of natural antioxidants (curcumin, quercetin, catechin, and vitamin E) as radical scavengers and stabilizers.
View Article and Find Full Text PDFNoncovalent, dye-mediated interactions between organo-montmorillonites ("organoclays") and a chitosan-based polyelectrolyte are exploited for highly effective and fast removal of different, industrially important anionic dyes (single-azo, double-azo, and anthraquinone) from aqueous solutions. The addition of only 10 wt % of the polyelectrolyte to conventional organoclay results in a 100% increase in absolute dye uptake capacity, an acceleration of dye uptake kinetics by up to 500%, and the flocculation of large, easily separable sorbent aggregates. These substantial improvements in adsorption performance are driven by the mediating effect of the anionic dyes (acting as the electrostatic mediator between the positively charged polyelectrolyte chains and organoclays), enabling the formation of true hybrid sorbent structures without the need for covalent cross-linking chemistry.
View Article and Find Full Text PDFThe structural evolution of cost-effective organo-clays (montmorillonite modified with different loadings of CTAB (cetyltrimethylammonium bromide)) is investigated and linked to the adsorption uptake and mechanism of an important industrial dye (hydrolyzed Remazol Black B). Key organo-clay characteristics, such as the intergallery spacing and the average number of well-stacked layers per clay stack, are determined by low-angle X-ray diffraction, while differential thermogravimetric analysis is used to differentiate between surface-bound and intercalated CTAB. Insights into the dye adsorption mechanism are gained through the study of the adsorption kinetics and through the characterization of the organo-clay structure and surface charge after dye adsorption.
View Article and Find Full Text PDFOrganogels prepared with vegetable oils as the liquid organic phase present an excellent platform for the controlled delivery of hydrophobic guest molecules. We disclose a graft copolymer comprised of a poly(L-serine) backbone linked to alkane side-chains by hydrolytically susceptible ester bonds, that is capable of gelating edible safflower oil. The thermoresponsive organogel formed, which is non-cytotoxic, is capable of withholding guest molecules before undergoing targeted disassembly upon incubation in solutions of acidic pH, permitting the directed release of payload molecules.
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