scholarly journals Volume Fraction Measurement of Soft (Dairy) Microgels by Standard Addition and Static Light Scattering

2021 ◽  
Author(s):  
Anisa Heck ◽  
Stefan Nöbel ◽  
Bernd Hitzmann ◽  
Jörg Hinrichs
Keyword(s):  
Light Scattering ◽  
Apparent Viscosity ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Standard Addition ◽  
Static Light Scattering ◽  
Soft Particle ◽  
Size Distributions ◽  
Functional Relationships ◽  
Wide Range

AbstractThe volume fraction of the dispersed phase in concentrated soft (dairy) microgels, such as fresh cheese, is directly related to structure and rheology. Measurement or modeling of volume fraction for soft and mechanically sensitive microgel dispersions is problematic, since responsiveness and rheological changes upon mechanical input for these systems limits application of typical functional relationships, i.e., using apparent viscosity. In this paper, we propose a method to measure volume fraction for soft (dairy) microgel dispersions by standard addition and volume-weighted particle size distributions obtained by static light scattering. Relative particle volumes are converted to soft particle volume fraction, based on spiked standard particle volumes. Volume fractions for two example microgel dispersions, namely, differently produced fresh cheeses, were evaluated before and after post-treatments of tempering and mechanical processing. By selecting the size of standard particles based on size ratios and the levels of the mixing ratios/relative fractions, the method could be applied robustly within a wide range of particle sizes (1 to 500 μm) and multimodal size distributions (up to quadmodal). Tempering increased the volume fraction for both example microgel dispersions (P < 0.05). Subsequent mechanical treatment reduced the volume fraction back to the starting value before tempering (P < 0.05). Furthermore, it was shown that the increase and successive decrease in apparent viscosity with tempering and mechanical post-treatments is not exclusively due to particle aggregation and breakdown, but to volume changes of each particle. For environmentally responsive soft matter, the proposed method is promising for measurement of volume fraction.

Size Distributions out of Static Light Scattering: Inclusion of Distortions from the Experimental Setup, e.g., a SOFICA-type Goniometer

1999 ◽  
Vol 215 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Jan Carsten Hansen ◽  
Dieter Maier ◽  
Josef Honerkamp ◽  
Walter Richtering ◽  
Frank Michael Horn ◽  
...  
Keyword(s):  
Light Scattering ◽  
Static Light Scattering ◽  
Experimental Setup ◽  
Size Distributions

scholarly journals Research on the Homogenized Postirradiation Elastoplastic Constitutive Relations for Composite Nuclear Fuels

2021 ◽  
Vol 8 ◽  
Author(s):  
Jing Zhang ◽  
Jingyu Zhang ◽  
Haoyu Wang ◽  
Hongyang Wei ◽  
Changbing Tang ◽  
...  
Keyword(s):  
Metal Matrix ◽  
Volume Fraction ◽  
Constitutive Relations ◽  
Particle Volume Fraction ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Particle Volume ◽  
Plastic Deformations ◽  
Wide Range ◽  
Irradiation Process

A multi-scale finite element method is developed to simulate the irradiation process and postirradiation uniaxial tensile tests for metal-matrix composite fuels with representative volume elements (RVEs). The simulations of irradiation process are implemented under a wide range of burnup levels, with the irradiation effects on the mechanical constitutive relations of fuel particles and matrix taken into account comprehensively. The simulation results for the macroscopic postirradiation true stress/strain curves are obtained, excluding the irradiation-induced macroscopic deformations. The effects of particle fission density, temperature, and initial particle volume fraction are investigated and analyzed. The research results indicate that 1) a quasi-elastic stage appears during the postirradiation tension, which is mainly induced by the creation of high residual compressive stresses in the particles and matrix after irradiation; 2) with the increase of effective strains, new plastic deformations increase in the particles and matrix to result in the macroscale plastic stage; 3) the macroscale irradiation softening and hardening phenomena appear, which mainly stem from the weakened deformation resistance by the irradiation-induced plastic deformations in the matrix, the enlarged particle volume fraction after irradiation, and the irradiation hardening effects of metal matrix.

Spatial and temporal spreading behaviors of light in glass particle-dispersed epoxy matrix composites evaluated by pico-second order light pulse profile

2003 ◽  
Vol 18 (11) ◽  
pp. 2644-2652 ◽  
Author(s):  
K. Matsumura ◽  
Y. Kagawa
Keyword(s):  
Light Scattering ◽  
Light Pulse ◽  
Epoxy Matrix ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Glass Particle ◽  
Second Order ◽  
Light Transmittance ◽  
Light Path ◽  
Pulse Profile

The light diffusion behavior in a glass particle-dispersed epoxy matrix composite was evaluated using a pico-second order light pulse. Change in pulse profile was detected, and this change in different detection areas is discussed. The light scattering behavior in the composite was directly observed, and the result was compared with the pulse profile change. This change appeared in the pulse shape, and depended on the particle volume fraction and the area of light detected. The maximum probable light path extension and the light transmittance were strongly correlated with the direct observation result of spatial spreading behavior of light in the composite. The combination use of (i) maximum probable light path extension and (ii) light transmittance was effective in evaluating the light-scattering behavior of the composite. The method is applicable to evaluation of the light-scattering process in light-transmitting materials.

Dynamics of Concentrated Colloidal Suspensions

1989 ◽  
Vol 177 ◽  
Author(s):  
D. A. Weitz ◽  
L. Ye ◽  
Ping Sheng ◽  
J. S. Huang ◽  
D. J. Pine ◽  
...  
Keyword(s):  
Light Scattering ◽  
Acoustic Waves ◽  
Volume Fraction ◽  
Brillouin Scattering ◽  
Particle Diameter ◽  
Colloidal Suspensions ◽  
Colloid System ◽  
Wide Range ◽  
Diffusive Modes ◽  
Pmma Particles

ABSTRACTWe study the dynamics of concentrated colloidal suspensions by measuring the frequency dependent structure factor, S(q,w), using light scattering techniques. We introduce Diffusing Wave Spectroscopy, which extends dynamic light scattering to the multiple scattering regime, allowing us to study the lower frequency, diffusive modes of S(q,w), which reflect the Brownian motion of the particles. We study the behavior of the higher-frequency, propagating modes of S(q,w), which reflect acoustic waves, using Brillouin scattering. To study S(q,w) at low qa, where q is the scattering vector and a the particle diameter, we use inverted micelles, and find that the interactions between the micelles has a dramatic impact on the speed of sound as the volume fraction of micelles increases. To study S(q,w) at large qa, we use index matched PMMA particles, allowing us to measure the dispersion curve of phonons in a hard sphere colloid system. Together, these results provide a measure of S(q, w) over a wide range of q and of w.

Small-Angle Neutron Scattering and 27Al Nmr Studies on the Microstructure and Composition of Alumina Sol-Gels

1990 ◽  
Vol 180 ◽  
Author(s):  
L. F. Nazar ◽  
D. G. Napier ◽  
D. Lapham ◽  
E. Epperson
Keyword(s):  
Light Scattering ◽  
Neutron Scattering ◽  
Acid Concentration ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Fractal Dimensions ◽  
Static Light Scattering ◽  
Scattering Data ◽  
Wide Range ◽  
Alumina Sol

ABSTRACTWe have used small angle neutron scattering, static light scattering and 27Al NMR to examine the structure and composition of alumina sol-gels formed by the hydrolysis of aluminum alkoxides. For LT sols at low acid concentrations, and HT gels over a wide range of acid concentration, 27Al solution NMR suggests, by the dearth of spectral resonances, that high molecular weight species are being formed. Analysis of the small angle neutron scattering data in the Porod regime indicates these sol-gels exhibit a power-law dependence consistent with mass fractal dimensions ranging from 1.45 to 1.8. These fractal dimensions are consistent with models based on diffusion limited cluster aggregation. The fractal dimensions do not differ significantly between LT and HT sols at the same acid concentration. However, for both temperature regimes, the fractal dimension increases with increasing acid concentration, suggesting a progression to a more compact network. Static light scattering measurements indicate the Guiner radii of the cluster aggregates vary from 600 to 2000Å.

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