Influence of Chain Charge and Complexation on the Overlap and Entanglements Formation in Poly(acrylic acid) Salt-Containing Aqueous Solutions

Литманович, Е. А.; Zakharchenko, Svetlana O.; Stoichev, Georgi V.

doi:10.1021/jp070070t

Cited by 25 publications

(21 citation statements)

References 8 publications

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“…For this purpose several definitions of c * have been proposed which can differ up to factor 10 . The main criterion for its determination is the magnitude of the volume occupied by a random coil at c *, therefore c * ∼ 1/[ η ] whereas it is also supposed that c * ≈ 1/[ η ] . Sometimes c * is arbitrarily determined as the concentration corresponding to a viscosity twice of the solvent with η rel = 2 or η spec = 1 where η rel and η spec are relative and specific viscosity respectively being defined as:

η_{rel} = \frac{η}{η_{0}}

η_{spec} = \frac{η - η_{0}}{η_{0} = η_{rel} - 1}

…”

Section: Resultsmentioning

confidence: 99%

Characterization of highly substituted, cationic amphiphilic starch derivatives: Dynamic surface tension and intrinsic viscosity

et al. 2013

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The surface activity and viscometric behavior of highly substituted, amphiphilic polysaccharides, derived from potato starch by modification with benzyl‐ and hydroxypropyl‐trimethylammonium groups, are studied in salt‐free and 0.05 M NaCl aqueous solution. For the first time dynamic surface tension measurements of amphiphilic starch derivatives have been effected using the pendant drop method and it was possible to correlate them with particle sizes and apparent charge density. Rheological investigation of large concentration ranges (0.01–20 g/L) is used to discuss Huggins plots and typical polyelectrolyte (PEL) behavior for all starch derivative samples could be found. The determination of overlap concentration and, in dilute aqueous solution, of intrinsic viscosity was possible. For the latter one the semi‐empirical equation of Rao was used, making it possible to get insights to PEL conformation in dependence on the degrees of substitution (DS) of both substituents. It is shown that for intrinsic viscosity an inversion of the impact of both substituents takes place, with hydrophobic benzyl groups on the one hand and cationic hydroxypropyl‐trimethylammonium groups on the other. Data evaluation via the ratio of both DS values had been successfully utilized and thus, the applied method has been identified as being a promising tool to compare a multitude of starch derivatives with substituents of different polarity in various DS to get tendencies regarding overall hydrophobicity.

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η_{rel} = \frac{η}{η_{0}}

η_{spec} = \frac{η - η_{0}}{η_{0} = η_{rel} - 1}

…”

Section: Resultsmentioning

confidence: 99%

Characterization of highly substituted, cationic amphiphilic starch derivatives: Dynamic surface tension and intrinsic viscosity

et al. 2013

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“…The main criterion for its determination is the magnitude of the volume occupied by a random coil at C*, therefore C* ∼ 1/[Á] (Qicong & Chu, 1987), but many times it is assumed that C* ≈ 1/[Á] (Candeau, Regalado, & Selb, 1998;Frish & Simha, 1956;Litmanovich, Zakharchenko, & Stoichev, 2007). Sometimes, C* value is arbitrarily determined as the concentration corresponding to a viscosity twice that of the solvent (i.e.…”

Section: Intrinsic Viscosities In Dilute Regimementioning

confidence: 99%

Hydrodynamic properties of some cationic amphiphilic polysaccharides in dilute and semi-dilute aqueous solutions

Nichifor¹,

Stanciu²,

Ghimici³

et al. 2011

Carbohydrate Polymers

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“…The more favorable the polymer-solvent interactions, the smaller the value of K H (Sakai 1968). The overlap concentration (C*) is the concentration at which polymer coils begin to overlap with each other and can be calculated by the inverse of (g) (Gupta et al 2005;Litmanovich et al 2007). The better the solvent, the smaller C* value.…”

Section: Solution Behaviormentioning

confidence: 99%

Solution behavior and surface properties of carboxymethylcellulose acetate butyrate

et al. 2009

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Solution behavior of carboxymethylcellulose acetate butyrate (CMCAB) in acetone and ethyl acetate has been investigated by small-angle X-ray scattering (SAXS) and capillary viscometry and correlated with the characteristics of CMCAB films. Viscosity and SAXS measurements showed that ethyl acetate is a better solvent than acetone for CMCAB. Thin films of CMCAB were deposited onto silicon wafers (Si/SiO 2 ) by spin coating. AFM images revealed that CMCAB spin coated films from solutions prepared in ethyl acetate were homogeneous and flat. However, films obtained from solutions in acetone were very rough. Contact angle measurements with polar and apolar test liquids characterized CMCAB surfaces as hydrophobic and allowed estimating the surface energy of CMCAB. Sum frequency generation vibrational spectroscopy was used to understand the role played by solvents and to gain insight about molecular orientation at Si/SiO 2 /CMCAB interface.

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Influence of Chain Charge and Complexation on the Overlap and Entanglements Formation in Poly(acrylic acid) Salt-Containing Aqueous Solutions

Cited by 25 publications

References 8 publications

Characterization of highly substituted, cationic amphiphilic starch derivatives: Dynamic surface tension and intrinsic viscosity

Characterization of highly substituted, cationic amphiphilic starch derivatives: Dynamic surface tension and intrinsic viscosity

Hydrodynamic properties of some cationic amphiphilic polysaccharides in dilute and semi-dilute aqueous solutions

Solution behavior and surface properties of carboxymethylcellulose acetate butyrate

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