Dynamic Surface Tension of Aqueous Polymer Solutions, I: Ethyl(hydroxyethyl)cellulose (BERMOCOLL cst-103)

Nahringbauer, Inger

doi:10.1006/jcis.1995.9961

Cited by 112 publications

(101 citation statements)

References 18 publications

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“…Figure 4 shows the surface tension of chitosan aqueous solutions and the first conclusion is that the value of this physical property shows a slow dynamic and, then, this property changes its value throughout the time until reaching a constant value. Different studies have obtained experimental results in agreement with these present data for different polymers aqueous solutions (Gau, Yu, & Zografi, 1993;Makri & Doxastakis, 2007;Nahringbauer, 1995).…”

Section: Resultssupporting

confidence: 91%

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Physicochemical characterization of chitosan derivatives

Seoane

Abuín

Gómez‐Díaz

et al. 2013

CyTA - Journal of Food

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The present work analyses different chitosan synthesized derivatives from the point of view of their chemical structure (Fourier transform infrared spectroscopy, deacetylation degree, elemental analysis and average molecular weight) as well as different physicochemical properties such as density, kinematic and dynamic viscosity, intrinsic viscosity and surface tension. The characterization of different solutions of these solutes has a high importance due to the large potential uses of these compounds. Chitosan has low solubility in water, and for this reason, the present work has synthesized soluble chitosan derivatives. Important differences between original chitosan and synthesized derivatives have been found in different properties.Keywords: chitosan; derivatives; viscosity; surface tension El presente trabajo analiza distintos derivados sintetizados del quitosano desde el punto de vista de su estructura quı´mica (FTIR, grado de desacetilacio´n, ana´lisis elemental y peso molecular medio), ası´como de distintas propiedades fı´sico-quı´mica como son la densidad, viscosidad cinema´tica y dina´mica, viscosidad intrı´nseca y tensio´n superficial. La caracterizacio´n de las disoluciones acuosas de estos solutos tiene una elevada importancia debido al gran potencial en el uso de estos compuestos. El quitosano tiene una baja solubilidad en agua y por este motivo este trabajo ha sintetizado derivados solubles de quitosano. Se han encontrado diferencias importantes en algunas propiedades entre los resultados experimentales correspondientes al quitosano y a sus derivados.

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Section: Resultssupporting

confidence: 91%

“…Also, the surface tension is an interesting attribute to analyse when polymer *Corresponding author. Email: josemanuel.navaza@usc.es aqueous solutions are used, since this kind of liquid systems commonly show a dynamic behaviour (Nahringbauer, 1995(Nahringbauer, , 1997.…”

Section: Introductionmentioning

confidence: 99%

Physicochemical characterization of chitosan derivatives

Seoane

Abuín

Gómez‐Díaz

et al. 2013

CyTA - Journal of Food

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“…In different papers, it is suggested that the polymers adsorbed at the interfaces forming loops and trains on the basis of the hydrophobic group blocks the distribution, which is orientated toward the air at the water/air interface [12]. In other papers, it has been suggested that adsorption of hydrocolloids occurs with two consecutive or simultaneous stages: firstly, a slow diffusion of the coiled macromolecules from the bulk phase to the subsurface region is followed by adsorption of polymer segments at the surface with conformational change [14,24]. This allows interpreting our data, in which only the fraction of hydrophobic zones (substitution degree around three being insoluble in water) independently of the molar mass is involved in this process.…”

Section: Surface Activity Of Methylcellulosesmentioning

confidence: 99%

Interfacial Properties of Methylcelluloses: The Influence of Molar Mass

et al. 2014

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Abstract:The interfacial interactions of four methylcelluloses having the same average degree of substitution and distribution of methyl groups, but different molar masses, are studied at ambient temperature and at very low polymer concentrations. Firstly, the surface tension σ at the water/air interface is determined for the progressive addition of methylcellulose up to 100 mg/L; σ starts to decrease over 1 mg/L up to the critical aggregation concentration (CAC) at 10 mg/L. The curves describing the influence of polymer concentration on σ are independent of the molar mass at equilibrium. Secondly, the adsorption of methylcellulose on silica particles is estimated from ζ-potential measurements. The data are interpreted in terms of an increase of the adsorbed layer thickness at the interface when the molar mass of methylcellulose increases. It is concluded that methylcellulose is adsorbed, forming trains and loops at the interface based on the equilibrium between surface free energy and solvent quality.

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“…They also give information on the intermolecular interaction of the adsorbed surfactant molecules. The dynamic interfacial characteristics of the polymers have been studied on a time scale from 30 s to some hours using the pendant drop technique (5,6). It has been reported that the polymer molecules diffuse from the bulk to the interface; they are then adsorbed there and the procedure is followed by conformation changes.…”

Section: Introductionmentioning

confidence: 99%