Bildungsweise, Strukture und Anwendungsmöglichkeiten von Komplexen zwischen Polyelektrolyten und ionischen Farbstoffen (Literaturübersicht) Teil II: Komplexe zwischen anionischen Polymeren und kationischen Farbstoffen

Dawydoff, W.; Linow, K.‐J.; Philipp, B.

doi:10.1002/actp.1991.010421208

Cited by 9 publications

(6 citation statements)

References 60 publications

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“…The main advantage of conductometric titrations is the well-defined stoichiometry with one equivalent of base or acid referring to one COOH group if completely equilibrated. Such a general transferability of binding stoichiometries among different particles is not necessarily the case for colorimetric assays. , In fact, a general one-to-one binding stoichiometry has long been assumed for the TB assay, − but comparison with other established methods were only attempted in a few exceptional cases. Surprisingly, many of these case studies revealed inconsistencies, which were mainly interpreted as a consequence of surface polymer morphology (vide infra) instead of a discrepancy in binding stoichiometry, , as proposed herein for the first time.…”

Section: Discussionmentioning

confidence: 99%

Scope and Limitations of Surface Functional Group Quantification Methods: Exploratory Study with Poly(acrylic acid)-Grafted Micro- and Nanoparticles

et al. 2012

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The amount of grafted poly(acrylic acid) on poly(methyl methacrylate) micro- and nanoparticles was quantified by conductometry, (13)C solid-state NMR, fluorophore labeling, a supramolecular assay based on high-affinity binding of cucurbit[7]uril, and two colorimetric assays based on toluidine blue and nickel complexation by pyrocatechol violet. The methods were thoroughly validated and compared with respect to reproducibility, sensitivity, and ease of use. The results demonstrate that only a small but constant fraction of the surface functional groups is accessible to covalent surface derivatization independently of the total number of surface functional groups, and different contributing factors are discussed that determine the number of probe molecules which can be bound to the polymer surface. The fluorophore labeling approach was modified to exclude artifacts due to fluorescence quenching, but absolute quantum yield measurements still indicate a major uncertainty in routine fluorescence-based surface group quantifications, which is directly relevant for biochemical assays and medical diagnostics. Comparison with results from protein labeling with streptavidin suggests a porous network of poly(acrylic acid) chains on the particle surface, which allows diffusion of small molecules (cutoff between 1.6 and 6.5 nm) into the network.

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Section: Discussionmentioning

confidence: 99%

Scope and Limitations of Surface Functional Group Quantification Methods: Exploratory Study with Poly(acrylic acid)-Grafted Micro- and Nanoparticles

et al. 2012

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“…Polyelectrolyte−dye complexation in solution has been extensively studied. − It is believed that these interactions depend strongly on electrostatic forces between the polymer and the dye, on the polymer's persistence length or conformational adaptability, and on the polymer's degree of cross linking. , In general, a linear polymer complexes dye less efficiently than a coiled or cross-linked polymer . These factors probably influence dye extraction from a surface by the polyion during multilayer formation.…”

Section: Introductionmentioning

confidence: 99%

Nonmonotonic Effect of Ionic Strength on Surface Dye Extraction during Dye−Polyelectrolyte Multilayer Formation

1998

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Multilayer formation between organic dyes and polyions is complicated by the possible competition between dye extraction from the surface by the polymer solution instead of polymer adsorption. We study the effects of salt concentration (NaCl, Na2SO4, MgCl2, and MgSO4) on this process and note that significant fractions of the dye are removed from the surface at intermediate salt concentration but that at lower or higher salt concentration less surface dye extraction occurs. Polymer solutions with intermediate NaCl concentrations show more than 60% dye extraction, while those of MgCl2, Na2SO4, and MgSO4 show approximately 30%, 25%, and 20% dye extraction, respectively. The maximum in dye extraction for all of these salts occurs when the solution Debye length is approximately 2 Å. The reduced efficiency of dye complexation away from the maximum is interpreted in terms of the polymer's expected increase in persistence length (low salt concentration) and the reduced electrostatic interactions between the charged dye and polymer (high salt concentration). The absorbance of poly(styrenesulfonate) remains roughly constant or slightly increases for the 1:1 and 2:2 salts but decreases with increasing 2:1 salt concentration. We propose that this decrease is due to charge reversal on the polymer or surface by the salt. Small shifts in dye peak positions suggest changes in the polarity of the surrounding matrix.

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“…After mixing, their mixtures were cloudy, suggesting complexation between the analyte and the PE. Complexation has previously been observed in solution between PEs and water-soluble, charged organic dyes [18,19]. Some enhancement in ion yield was also observed from a dried droplet of a simple binary solution of an analyte and a polyelectrolyte.…”

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confidence: 67%

Polyelectrolytes as new matrices for secondary ion mass spectrometry

Lua

Pew

et al. 2005

J. Am. Soc. Mass Spectrom.

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Significant enhancements in ion yields in time-of-flight secondary ion mass spectrometry (TOF-SIMS) are observed when water-soluble analytes are mixed with a polyelectrolyte, e.g., poly(diallyldimethylammonium chloride) or poly(sodium 4-styrenesulfonate), and then deposited in the layer-by-layer method on a surface. This previously unobserved effect is demonstrated for 5-chloro-8-methoxyquinoline appended diaza-18-crown-6, 5-(2-aminoethoxy)methyl-5-chloro-8-methoxyquinoline appended diaza-18-crown-6, acridine, 9-anthracenecarboxylic acid, and ferrocenecarboxylic acid. By optical ellipsometry film thicknesses range from ca. 5-20 Å. X-ray photoelectron spectroscopy shows significantly less analyte in the polyelectrolyte-analyte films than in the neat analytes. However, TOF-SIMS generally shows significant enhancements in ion yields from the polyelectrolyte films compared with either the neat compounds or the compounds solubilized with acid or base and then dried on a surface. These significant enhancements in ion yields also appear to extend to analyte fragments and cationized molecular species. Some enhancement is also observed for dried droplets of analytes mixed with a polyelectrolyte on surfaces. (J Am Soc Mass Spectrom 2005, 16, 1575-1582

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Bildungsweise, Strukture und Anwendungsmöglichkeiten von Komplexen zwischen Polyelektrolyten und ionischen Farbstoffen (Literaturübersicht) Teil II: Komplexe zwischen anionischen Polymeren und kationischen Farbstoffen

Cited by 9 publications

References 60 publications

Scope and Limitations of Surface Functional Group Quantification Methods: Exploratory Study with Poly(acrylic acid)-Grafted Micro- and Nanoparticles

Scope and Limitations of Surface Functional Group Quantification Methods: Exploratory Study with Poly(acrylic acid)-Grafted Micro- and Nanoparticles

Nonmonotonic Effect of Ionic Strength on Surface Dye Extraction during Dye−Polyelectrolyte Multilayer Formation

Polyelectrolytes as new matrices for secondary ion mass spectrometry

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