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Triton X-100 Micelles (triton + x-100_micelle)
Selected AbstractsPhotoreduction of iron protoporphyrin IX chloride in non-ionic triton X-100 micelle studied by electronic absorption and resonance Raman spectroscopyJOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2001P. K. Shantha Resonance Raman and electronic absorption studies of iron protoporphyrin IX chloride (hemin) in non-ionic Triton X-100 micelle in the absence and presence of hindered imidazole (2-methylimidazole and 1,2-dimethylimidazole) and unhindered imidazole under various experimental conditions are reported. Hemin undergoes photoreduction at the metal center, both in the absence and presence of hindered imidazole, in anaerobic, alkaline and neutral pH conditions on photoexcitation by laser radiation at 441.6 and 457.9 nm. It is inferred from this study that only the monomer hemin encapsulated within the micelle under the alkaline pH conditions is photoreducible. The photoreduction of hemin in this micelle occurs from an electron transfer as a result of dissociation of coordinated hydroxyl ion to the iron atom in the photoexcited state, which may also involve the OH,Fe charge transfer transition around 360 nm. Copyright © 2001 John Wiley & Sons, Ltd. [source] Fabrication of poly(aniline- co -pyrrole) hollow nanospheres with Triton X-100 micelles as templatesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2008Chuanqiang Zhou Abstract A one-step route has been reported for the fabrication of poly(aniline- co -pyrrole) (PACP) copolymer hollow nanospheres via the oxidation polymerization of a mixture of aniline and pyrrole in the presence of Triton X-100. It was found that the variations in polymerization conditions, such as the concentrations of Triton X-100 and comonomers, and [pyrrole]/[aniline] molar ratios, could change the size and uniformity of copolymer hollow nanospheres. The result of DLS has attested the presence of the spherical Triton X-100 micelles swelled by the comonomers in reaction system, and such micelles might play template for the formation of hollow nanospheres, followed by developing a possible formation mechanism. The chemical structures and crystallinity of products were characterized by FTIR, UV,visible, 1H NMR spectra, and XRD patterns, respectively, to prove the copolymer chemical structures of hollow nanospheres. The thermal-stability and solubility of PACP were improved compared with homopolymers (polyaniline and pyrrole). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3563,3572, 2008 [source] Environmental Effects on the Photochemistry of A2-E, a Component of Human Retinal Lipofuscin,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2001Laura Ragauskaite ABSTRACT Several retinal dystrophies are associated with the accumulation of lipofuscin, a pigment mixture, in the retinal pigment epithelium (RPE). One of the major fluorophores of this mixture has been identified as the bis-retinoid pyridinium compound, A2-E. Because this compound absorbs incident radiation that is transmitted by the anterior segment of the human eye, photophysical and photochemical studies were performed to determine if A2-E could photosensitize potentially damaging reactions. Steady-state fluorescence measurements indicate that the fluorescence emission maximum and quantum yield are very sensitive to the chemical environment and a correlation between these two parameters and the solvent dielectric constant is observed. Time-resolved absorption experiments of A2-E in pure organic solvents showed no formation of transient species on the timescale of our experiments. However, when these measurements were repeated for A2-E in Triton X-100 micelles, a short-lived (,, 14 ,s), weak absorption was observed. This species is quenched by oxygen (k= 2 × 109M,1 s,1) and by the addition of the antioxidants, cysteine and N,N,N,,N, -tetramethylphenylenediamine. Quenching of this species by 2,3,5-trimethylhydroquinone results in the formation of the 2,3,5-trimethylsemiquinone free radical and an increase in yield of the A2-E,derived species. Sensitization of the A2-E triplet excited state indicates that the species observed in micelles upon direct excitation is not consistent with the triplet excited state. Based on these data we tentatively assign this absorption to a free radical. In the RPE these initial processes can ultimately lead to damage to the tissue through the formation of peroxides and other oxidized species. [source] Study of influence of additives of tyloxapol on the chromatographic characteristics of the model compounds: the comparative characterization of micellar mobile phases of tyloxapol and Triton X-100BIOMEDICAL CHROMATOGRAPHY, Issue 7 2009Marina Rukhadze Abstract The chromatographic behavior of model compounds of biomedical significance (organic acids, amino acids, drugs) was investigated using mobile phases modified with tyloxapol. The influence of factors such as concentration of tyloxapol, content of organic modifier and pH of mobile phase on the retention factor of solutes was studied. The results were compared with the data obtained by elution with mobile phases containing Triton X-100 additives, since units of Triton X-100 are repeated in the structure of tyloxapol. Divergence in chromatographic behavior of model compounds was explained by the difference in physico-chemical characteristics (microviscosity, polarity, critical micelle concentration, shape of micelles, etc.) of tyloxapol and Triton X-100 micelles. Copyright © 2009 John Wiley & Sons, Ltd. [source] Photoreduction of iron protoporphyrin IX chloride in non-ionic triton X-100 micelle studied by electronic absorption and resonance Raman spectroscopyJOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2001P. K. Shantha Resonance Raman and electronic absorption studies of iron protoporphyrin IX chloride (hemin) in non-ionic Triton X-100 micelle in the absence and presence of hindered imidazole (2-methylimidazole and 1,2-dimethylimidazole) and unhindered imidazole under various experimental conditions are reported. Hemin undergoes photoreduction at the metal center, both in the absence and presence of hindered imidazole, in anaerobic, alkaline and neutral pH conditions on photoexcitation by laser radiation at 441.6 and 457.9 nm. It is inferred from this study that only the monomer hemin encapsulated within the micelle under the alkaline pH conditions is photoreducible. The photoreduction of hemin in this micelle occurs from an electron transfer as a result of dissociation of coordinated hydroxyl ion to the iron atom in the photoexcited state, which may also involve the OH,Fe charge transfer transition around 360 nm. Copyright © 2001 John Wiley & Sons, Ltd. [source] |