Solvent polarity of aqueous polymer solutions as measured by the solvatochromic technique

Zaslavsky, Boris Y.; Miheeva, Larisa M.; Масимов, Э. А.; Djafarov, Sahib F.; Reichardt, Christian

doi:10.1039/ft9908600519

Cited by 40 publications

(39 citation statements)

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“…a, b, and s are coefficients reflecting the susceptibility of the polarity terms upon XYZ. Empirical solvatochromic polarity parameters [a, b, p*, E T (30)] for synthetic polymers, copolymers, native polymers, inorganic oxidic materials, functionalized silica particles, hybrids, and composite materials have been determined by means of the following solvatochromic probe dyes: 2,6-diphenyl-(2,4,6-triphenyl-1-pyridinio)-4-phenolate (1 a), Michler's ketone (2), dicyano-bis(1,10-phenanthrolin)iron II (3), and a novel aminobenzodifuranone dye (7). The solvatochromic band shifts of these indicators correlate precisely with the Kamlet-Taft solvent parameters a, b, and p*.…”

Section: Motivation and Conceptmentioning

confidence: 99%

“…The results are compared with each other, with related solvent model compounds, and literature values. The relation of the well established E T (30) solvent polarity scale to the Kamlet-Taft parameters a and p* of solid materials is demonstrated. Hence, a general polarity scale for solid materials is suggested.…”

Section: Motivation and Conceptmentioning

confidence: 99%

“…The following methods have been well established for investigating surface polarity properties of polymer films or fibres: chromatography [6][7][8][21][22][23] , contact angle measurements of liquid drops on the polymer surface for measuring the surface tension (CAT) [24][25][26] , zetapotential measurements in various liquids (ZP) 27,28) , and UV-Vis spectroscopy of solvatochromic probe dye molecules [29][30][31] . However, chromatography, CAT, and ZP seem only suitable to reflect the polarity effects of the interface between the polymer and a gaseous or/and liquid phase, respectively, whereas solvatochromic probe molecules can also be measured when included in polymer films, or incorporated in mycelles [32][33][34] , or in sol-gel produced hybrid materials 35) .…”

Section: Motivation and Conceptmentioning

confidence: 99%

“…Solvatochromically determined polarity parameters for synthetic polymers have been reported by several authors [29][30][31] . Kamlet-Taft p* values for synthetic polymers were firstly reported by Marks et al 42) The authors used those nitrosubstituted aromatic compounds which were originally used by Kamlet and Taft as solvatochromic polarity indicators for solvents 12,13) .…”

Section: Empirical Polarity Parameters Of Solid Materials -A Brief Rementioning

confidence: 99%

“…A. The polymer and the solvatochromic dye together is dissolved in a suitable liquid and then the UV-Vis spectrum of the indicator is measured as a solution 30) . In this case an average polarity of the solvent and polymer is obtained similar to those results obtained for solvent mixtures 58) .…”

Section: Synthetic Polymersmentioning

confidence: 99%

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Empirical polarity parameters for various macromolecular and related materials

Spange¹,

Vilsmeier

Fischer

et al. 2000

Macromol. Rapid Commun.

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Empirical polarity parameters are recommended as useful characteristics for describing the internal and external surface properties of various solid materials, e. g. synthetic polymers, native polymers, inorganic oxides, sol‐gel hybrids, and composites. The polarity properties of a macromolecule have been expressed by three independent terms: the α value (the hydrogen bond donating, HBD, capacity or acidity), the β value (the hydrogen bond accepting, HBA, capacity or basicity), and the π* value (the dipolarity/polarizability). These terms can be defined using the Kamlet‐Taft solvents parameter set as the reference system. A complex property, XYZ, of a macromolecular material under study, with reference to a standard system (XYZ)0 (i. e. gas phase or a nonpolar polymer), can then be described by a simplified Kamlet‐Taft LSE (linear solvation energy) equation: XYZ = (XYZ)0 + sπ* + aα + bβ. a, b, and s are coefficients reflecting the susceptibility of the polarity terms upon XYZ. Empirical solvatochromic polarity parameters [α, β, π*, ET (30)] for synthetic polymers, copolymers, native polymers, inorganic oxidic materials, functionalized silica particles, hybrids, and composite materials have been determined by means of the following solvatochromic probe dyes: 2,6‐diphenyl‐(2,4,6‐triphenyl‐1‐pyridinio)‐4‐phenolate (1 a), Michler's ketone (2), dicyano‐bis(1,10‐phenanthrolin)iron II (3), and a novel aminobenzodifuranone dye (7). The solvatochromic band shifts of these indicators correlate precisely with the Kamlet‐Taft solvent parameters α, β, and π*. The results are compared with each other, with related solvent model compounds, and literature values. The relation of the well established ET (30) solvent polarity scale to the Kamlet‐Taft parameters α and π* of solid materials is demonstrated. Hence, a general polarity scale for solid materials is suggested.

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Section: Motivation and Conceptmentioning

confidence: 99%

Section: Motivation and Conceptmentioning

confidence: 99%

Section: Motivation and Conceptmentioning

confidence: 99%

Section: Empirical Polarity Parameters Of Solid Materials -A Brief Rementioning

confidence: 99%

Section: Synthetic Polymersmentioning

confidence: 99%

See 3 more Smart Citations

Empirical polarity parameters for various macromolecular and related materials

Spange¹,

Vilsmeier

Fischer

et al. 2000

Macromol. Rapid Commun.

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Physico‐chemical features of solvent media in the phases of aqueous polymer two‐phase systems

Zaslavsky

Borvskaya

Gulaeva

et al. 1992

Biotech & Bioengineering

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Solvent polarity and pH in the coexisting aqueous phases of aqueous dextran-poly(ethylene glycol) and dextran-Ficoll two-phase systems of varied polymer concentrations were examined using the solvatochromic technique and potentiometric measurements, respectively. The relative solvent polarity of the phases, as measured by the solvatochromic technique, is suggested as a measure of the hydration power of water in the phases of aqueous polymer systems. Partitioning of a series of sulphonephthalein dyes in aqueous dextran-poly(ethylene glycol) and dextran-Ficoll two-phase systems of fixed polymer composition containing 0.01 mol/L universal buffer, pH 7.15, was studied. The results obtained are discussed together with those reported earlier on the physico-chemical features of aqueous media in the coexisting phases of the systems. It is suggested that the two phases of aqueous polymer systems should be viewed as two immiscible water-like solvents. The implications of the suggestion for the theoretical treatment of aqueous polymer two-phase systems are discussed.

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Solvatochromism of Sterically Hindered Stilbazolium Betaines and Its Relationship to Reichardt's E_T(30) Scale: The Problem of the Measurement of the Polarity vs the Acidity of Alcohols

et al. 1993

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The hydrogen bond acidity of twenty primary, secondary, and tertiary alkanols has been measured by the solvatochromic method by using three stilbazolium betaines: stilbazolium betaine itself (SB), o-tert-butyl-substituted (TBSB), and o,o'-ditert-butyl-substituted SB (DTBSB). The spectral differences between two of these betaines and in particular the k values which correspond to SB and DTBSB, The most exhaustively studied and most widely used empirical scale of solvent polarity is Reichardt's ET(30) scale" -']. This scale is based on the negative solvatochromism of pyridinium N-phenoxide betaine dye I, and it has been used as a measure of solvent polarity by Rei~hardt['-~] and othersf5]. However, Laurence, Reichardt et al.@l have examined the sensitivity of I to acidity in the case of acidic alcohols like CF3CH20H and to steric effects in the case of bulky alcohols like (CH&COH. Nevertheless, it is assumed that ET(30) measures essentially the solvent polarity.In a previous papertn we have shown that the extremely strong negative solvatochromism of the stilbazolium betaine dye SB I1 ( x 6500 cm-') is not due to the dipolarity-polarizability effect of the solvent but to its acidity (hydrogenbond donor acidity, HBD acidity). This has been proven by studying the solvatochromic effects of the same solvent on betaine DTBSB IV where the basic center, the oxygen atom, is protected against the approach of the solvent by the introduction of two bulky tert-butyl groups into the ortho position. When this specific solvent effect is prevented, stilbazolium betaines show only a very weak solvatochromism but their electronic spectra exhibit a coarse structure (see below for a definition of this term); vice versa, the appearance of a resolved maximum indicates steric hindrance to the approach of an HBD-acidic solvent. Betaine I is not so well protected against specific solvation effects by the two o-phenyl rings since they can rotate, i.e. the steric effect of a phenyl ring depends on conformation.We have synthesized the new betaine TBSB I11 bearing only one tert-butyl group in ortho position with respect to the basic center, in order to determine more precisely the HBD acidity of the solvents. Since the carbonyl group of stilbazolium betaines has two oxygen lone pairs that lie in the plane of the quinonoid ring, it is possible to have two (SB), one (TBSB), or no channel (DTBSB) for the approach of the acidic solvent depending on the number of o-tertbutyl groups. We have found that a comparative study of the electronic spectra of the three betaines in a series of twenty alcohols provides a measure of the acidity of alcohols in the condensed phase, with the only limitation that they must be liquids at room temperature, or near to it.The results are collected in Table 1 in which A corresponds to the wavenumber difference between SB and TBSB, A' to the wavenumber difference between SB and DTBSB, and A" to the wavenumber difference between TBSB and DTBSB. Thus, by definition, equation A' = A + A holds. According to the proposed mod...

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Solvent polarity of aqueous polymer solutions as measured by the solvatochromic technique

Cited by 40 publications

References 15 publications

Empirical polarity parameters for various macromolecular and related materials

Empirical polarity parameters for various macromolecular and related materials

Physico‐chemical features of solvent media in the phases of aqueous polymer two‐phase systems

Solvatochromism of Sterically Hindered Stilbazolium Betaines and Its Relationship to Reichardt's E_T(30) Scale: The Problem of the Measurement of the Polarity vs the Acidity of Alcohols

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Solvent polarity of aqueous polymer solutions as measured by the solvatochromic technique

Cited by 40 publications

References 15 publications

Empirical polarity parameters for various macromolecular and related materials

Empirical polarity parameters for various macromolecular and related materials

Physico‐chemical features of solvent media in the phases of aqueous polymer two‐phase systems

Solvatochromism of Sterically Hindered Stilbazolium Betaines and Its Relationship to Reichardt's ET(30) Scale: The Problem of the Measurement of the Polarity vs the Acidity of Alcohols

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Solvatochromism of Sterically Hindered Stilbazolium Betaines and Its Relationship to Reichardt's E_T(30) Scale: The Problem of the Measurement of the Polarity vs the Acidity of Alcohols