Intrinsic viscosity calculated out of single point measurements for chondroitin-4-sulfate and chondroitin-6-sulfate solutions

Arias, Concepción; Yagüe, A; Rueda, Carmen; Blanco, Francisco Garcı́a

doi:10.1016/s0301-4622(98)00113-6

Cited by 17 publications

(6 citation statements)

References 15 publications

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“…The temperature during this testing was held constant at 25 • C using a water bath connected to a Peltier system, and the angular velocity was 100 rpm. The intrinsic viscosity ([η]) was estimated via linear extrapolation at a zero concentration using the following equations [34]:…”

Section: Intrinsic Viscosity and Viscosity-average Molecular Weightmentioning

confidence: 99%

Physicochemical Properties and Antioxidant Activity of Pumpkin Polysaccharide (Cucurbita moschata Duchesne ex Poiret) Modified by Subcritical Water

Zhao

Wei

et al. 2021

Foods

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In this paper, subcritical water (SCW) was applied to modify pumpkin (Cucurbita moschata Duchesne ex Poiret) polysaccharides, and the properties and antioxidant activity of pumpkin polysaccharides were investigated. SCW treatments at varying temperature led to changes in the rheological and emulsifying properties of pumpkin polysaccharides. SCW treatments efficiently degraded pumpkin polysaccharides and changed the molecular weight distribution. Decreases in intrinsic viscosity, viscosity-average molecular weight, and apparent viscosity were also observed, while the activation energy and flow behavior indices increased. The temperature of SCW treatment has a great influence on the linear viscoelastic properties and antioxidant activity of pumpkin polysaccharides. Pumpkin polysaccharides solution treated by SCW at 150 °C exhibited the highest emulsifying activity and antioxidant activity, which was probably due to a broader molecular mass distribution and more reducing ends exposed after treatment. Scanning electron microscopy showed that SCW treatment changed the microstructure of pumpkin polysaccharides, resulting in the exposure of bigger surface area. Our results suggest that SCW treatment is an effective approach to modify pumpkin polysaccharides to achieve improved solution properties and antioxidant activity.

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Section: Intrinsic Viscosity and Viscosity-average Molecular Weightmentioning

confidence: 99%

Physicochemical Properties and Antioxidant Activity of Pumpkin Polysaccharide (Cucurbita moschata Duchesne ex Poiret) Modified by Subcritical Water

Zhao

Wei

et al. 2021

Foods

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“…It has been reported that the intrinsic viscosity can be considered as a criterion of the hydrodynamic volume of molecules in a dilute solution, and is generally dependent on the dimensions of the polymer chain and the polymer–solvent interaction . Although the dispersion of collagen in solution does not exclude the possibility of the presence of colloidal collagen particles, the main focus of this experiment is to study the interactions of collagen molecules in different concentrations of AA solution, through reporting the relative changes in [η] and k H , rather than obtaining the true absolute values of intrinsic viscosity .…”

Section: Resultsmentioning

confidence: 99%

“…The flow times were measured with a digital stopwatch at least five times, and the average was taken . The [η] of the collagen solutions was estimated by the expressions of Huggins:

\frac{{normalη}_{s p}}{C} = [η] + k_{H} {[η]}^{2} C

{normalη}_{s p} = \frac{t - t_{0}}{t_{0}}

where

\frac{{normalη}_{s p}}{C}

is the reduced viscosity, C (g/dL) is the concentration of the collagen solution, k H is the Huggins coefficient, t is the flow time of the collagen solution and t 0 is the flow time of the solvent.…”

Section: Methodsmentioning

confidence: 99%

Investigation on the interaction of collagen molecules in solution with different acetic acid concentrations

Yang

Deng

et al. 2017

J of Applied Polymer Sci

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Collagen solutions in the presence of 0.1-2.0M acetic acid (AA) were investigated to understand the interaction between collagen molecules and an acidic solvent. Fluorescence measurements of pyrene showed that the critical aggregation concentration (CAC) of collagen increased from 0.518 to 1.581 mg/mL for AA concentrations ranging from 0.1 to 2.0M, indicating that the aggregated state of collagen molecules was associated with AA concentration. The size of the collagen aggregates, determined by dynamic light scattering, demonstrated that their disaggregation was enhanced with increasing electrostatic repulsion between the collagen chains. The variations in the intrinsic viscosity and Huggins coefficient depended on the molecular interaction among the collagen molecules. Furthermore, the increased AA concentration has a different influence on the rigidity of collagen molecules above and below the CAC. This observation was manifested by the changes in the morphology of collagen molecules observed by atomic force microscopy.

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“…In this section, special attention is paid to select the most suitable single‐point equation (SPE) for estimating PA 66 intrinsic viscosity ( η ) at a fixed concentration and to fit calibration models for intercoverting quickly and easily viscosity measurements. As it is well‐known, SPE leads to great reduction in experimental work, and a number of these viscosity functions are able to estimate η almost independently of concentration for many polymer solutions.…”

Section: Resultsmentioning

confidence: 99%

Modeling of Polyamide 66 Solid State Polymerization: Drawing a Chemical Reaction Scheme

Filgueiras

Vouyiouka

Konstantakopoulou

et al. 2014

Macro Reaction Engineering

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A chemical reaction scheme is proposed here to describe the polyamide 66 (PA 66) solid state polymerization (SSP) with effective kinetic parameters. The main objective of the suggested model is to predict the maximum molecular weight attainable at each SSP isotherm, which is in turn determined by the occurrence of polymer chain degradation coupled to other important side reactions. Accordingly, a number of side reactions have been firstly considered, based on which a comprehensive particle model was constructed to predict PA 66 kinetics, equilibrium, and transport phenomena. The SSP model parameters were estimated with a maximum-likelihood estimator, using data measured under kineticand diffusion-controlled process conditions for reaction temperatures in the range of 160-200 8C and reaction times up to 8 h. Calibration models were also developed to allow the determination of PA 66 solution viscosities.

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Intrinsic viscosity calculated out of single point measurements for chondroitin-4-sulfate and chondroitin-6-sulfate solutions

Cited by 17 publications

References 15 publications

Physicochemical Properties and Antioxidant Activity of Pumpkin Polysaccharide (Cucurbita moschata Duchesne ex Poiret) Modified by Subcritical Water

Physicochemical Properties and Antioxidant Activity of Pumpkin Polysaccharide (Cucurbita moschata Duchesne ex Poiret) Modified by Subcritical Water

Investigation on the interaction of collagen molecules in solution with different acetic acid concentrations

Modeling of Polyamide 66 Solid State Polymerization: Drawing a Chemical Reaction Scheme

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