Characterization Of Rheological Behavior Research Articles

The rheological behavior characterization and prediction of cement concrete containing magnetite (Fe3O4) and/or carbon fiber

The effect of magnetite and carbon fiber (CF) on the rheological properties of concrete was investigated to reflect and affect its engineering performance development. The rheological parameters of concrete were measured. Next, a prediction model was established to predict the change tendency in the rheological properties of concrete. Then, the correlation between rheological and mechanical properties was investigated to explore the mechanism of rheological behavior on its engineering performance. The results showed that magnetite and CF had a significant effect on the rheological behavior of concrete. When the magnetite and CF contents were 50 % and 0.5 wt%, the yield stress and plastic viscosity of concrete increased by 210.77 % and 35.88 %, respectively, compared to the control group. The physical properties of the materials, their interaction with the cement matrix and their effect on the volume fraction of the concrete system are the main factors affecting the rheological properties of concrete. Meanwhile, the prediction model established by using the nonlinear surface fitting function could effectively predict the influence of materials on the rheological behavior of concrete. The R2 between the predicted and measured values of yield stress could be up to 0.99. However, under the condition of large magnetite and CF content, the aggregation effect of the materials had a certain influence on the plastic viscosity of the concrete, resulting in a certain deviation between the predicted and measured values, but the R2 could still be up to 0.89. It indicated that the prediction model had favorable reliability and accuracy. A strong correlation existed between the rheological parameters and mechanical strength of concrete. The effect of magnetite and CF on rheological properties of concrete promoted the internal microstructure characteristics optimization of concrete to affect its mechanical properties.

Characterization of rheological behavior and barrier property of PET bottle blended with silica–polystyrene nanocomposites

Characterization of rheological behavior and barrier property of PET bottle blended with silica–polystyrene nanocomposites

The technological and nutritional advantages of emulsified sausages with partial back-fat replacement by succinylated chicken liver protein and pre-emulsified sunflower oil

This work aimed at exploring the potential of partial substitution of the back-fat with fat mimetic, a novel polysaccharide-protein complex of xanthan gum and succinylated chicken liver protein, to improve the physicochemical characteristics and fatty acid composition of emulsified sausages. The quality characteristics of the sausages demonstrated that low-fat emulsified sausages with the addition of fat mimetic or its sunflower oil pre-emulsion presented similar microstructure and texture to high-fat sausages, while pre-emulsion increased the gel strength and whiteness of products. The rheological behavior characterization indicated that fat replacers caused a significant increase in storage modulus and loss modulus, explaining well the decreased cooking loss and the improved emulsification stability, water holding capacity (WHC) and heating stability. Although the back-fat replacement led to a great decrease in fatty acids, the nutritional values of fatty acids were optimized due to the incorporation of sunflower oil, as revealed by a 10% increase of polyunsaturated fatty acids and the decreased TBARS values within the storage. This study suggests the technological feasibility to simultaneously improve the quality and nutritional features of emulsified sausages with partial back-fat replacement by the proposed polysaccharide-protein complex, as well as the way to achieve chicken liver valorization.

Erratum to: Flocculated flow of microfibrillated cellulose water suspensions: an imaging approach for characterisation of rheological behaviour

Erratum to: Flocculated flow of microfibrillated cellulose water suspensions: an imaging approach for characterisation of rheological behaviour

Formulation and physicochemical characterization of hydrogels with 18β-glycyrrhetinic acid/phospholipid complex phytosomes

Carbomer based hydrogels with 1% of 18β-glycyrrhetinic acid complex in the form of phytosomes (18β-GAP) were formulated by using Carbopol®980 and Carbopol®Ultrez 10 as gelling agents (1%), sodium hydroxide (neutralizing agent) (0.4%), glycerol (humectant) (10%), Sepicide® HB (preservative) (1%), and water (up to 100%). In order to prepare the hydrogels, 18β-GAP was dispersed into the water phase prior the carbomer neutralization or the 18β-GAP aqueous dispersion was added into the previously neutralized carbomer dispersion. The pH values (6.71 ± 0.16–7.09 ± 0.06), soft semisolid consistency and spreadability (25.7 ± 1.5 mm–33.7 ± 0.6 mm) of the hydrogels were acceptable for application on the skin. The influence of the preparation procedure, the carbomer type, and addition of a humectant (glycerol 10%) on physicochemical properties was evaluated using light microscopy, DSC analysis and rheological behavior characterization. The preparation procedure, the carbomer type, and the addition of the humectant did not affect significantly organoleptic and morphological characteristics and spreadability of the hydrogels. The Carbopol®980 based hydrogels were more sensitive than hydrogels based on Carbopol®Ultrez 10 upon thermal variations regarding the water evaporation loss. Physical stability of the investigated hydrogels was satisfactory for minimum 30 days of storage at a temperature range from +4 °C up to +40 °C.

Rheological Behavior Characterization of Natural Rubber Containing Different Gel

This research, natural rubber containing different gel contents were prepared by deproteinization and saponification treatment from high ammonium natural rubber latex. Deproteinization natural rubber was further treated as acetone extraction and then transesterification. It was founded that gel content and molecular weights of treated natural rubber were decreased and almost absented for transesterification treatment. Rheological respond on small amplitude oscillating shear (SAOS) and large amplitude oscillating shear (LAOS) deformation of treated natural rubber were captured by using rubber process analyzer (RPA 2000). Firs harmonic rheological properties, storage modulus, G and loss modulus, G decreased as gel content and molecular weight decreased. It was believed that gels, explicitly branching points, were destroyed after the natural rubber was deproteinized, transesterification, or saponification according to the molecular structure of natural rubber presumed by Tanaka et al, which functional groups contain protein and fatty acid are participated in branching to forming gel structure. It was concluded that gel content as the same as molecular structure of natural rubber could be characterized as rheological behavior.

Hydrodynamic Interaction of Particles in Al2O3Slurries Prepared by Different Milling Methods

The surface state of vapor-phase-synthesized nonhydrated Al2O3 particles after milling was investigated quantitatively. The amount and kind of materials generated were different depending on the milling methods used and the ball grinding media. Gibbsite and bayerite were formed on the surface of Al2O3 particles in ball and planetary ball millings, respectively. On the other hand, wet-jet milling led to an undamaged Al2O3 particle surface as compared with other milling methods that use ball grinding media, in which the hydration reaction on the particle surface was also suppressed. In this work, the hydrodynamic interaction between Al2O3 particles in slurries prepared by various milling methods was investigated by rheological behavior characterization. From the creep and recovery measurements, it was found that the ball-milled and planetary ball-milled slurries behaved elastically. In the case of the wet-jet-milled slurry, the strain was proportional to the measurement time, indicating that the slurry had a liquid-like behavior. The creep compliance values of the ball-milled, planetary ball-milled, and wet-jet-milled slurries were 5.2 × 10−3, 1.5 × 10−3, and 14.8 × 103 Pa−1, respectively, indicating that the fluidity of planetary ball-milled slurry was lower than that of the ball-milled one. The fluidity of the wet-jet-milled slurry was fairly strong as compared with the ball-milled and planetary ball-milled ones. Moreover, the dynamic viscoelastic properties of the resulting slurries were measured at low strains in order to examine the rheology at long time scales. The behavior of the wet-jet-milled slurry in poly(acrylic acid) (PAA-NH4+) solution was similar to that of the PAA-NH4+-only solution. Therefore, it was found that the wet-jet-milled particles were more mobile in the slurry, with liquid-like behavior, and the attractive interaction between particles was very weak as compared with the ball-milled and planetary ball-milled ones.

Une méthode d'identification inverse des paramètres matériels pour les comportements non-linéaires

ABSTRACT The characterization of rheological behaviour of materials in nonlinear range is based on experimental tests, characterized by non-homogeneous stress and strain states, making the direct identification very difficult to perform. In this paper, an inverse identification method is proposed to avoid the problems raised by the interpretation of the experimental tests and to determine more accurately material parameters. The algorithm developed consists of an optimization method and a finite element method. This algorithm is first tested by the determination of material parameters in the case of the nonlinear elastic behaviour of polymers, then applied to the inverse identification of viscoplastic parameters of an aluminium alloy.