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.

Effect of total particle surface area on the light transmittance of glass particle-dispersed epoxy matrix optical composites

2002 ◽  
Vol 17 (12) ◽  
pp. 3237-3241 ◽  
Author(s):  
Tamaki Naganuma ◽  
Yutaka Kagawa
Keyword(s):  
Laser Beam ◽  
Surface Area ◽  
Epoxy Matrix ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Particle Surface ◽  
Glass Particle ◽  
Light Transmittance ◽  
Particle Volume ◽  
Particle Surface Area

The effect of particle volume fraction fp on the light transmittance of glass particle-dispersed epoxy matrix composites with a particle volume fraction of fp = 0.0001 to 0.4 was studied. The particle size used was much larger than the wavelength of light in a visible wavelength. The transmitted laser beam scattering pattern and light transmittance of the composites were obtained, and the transmitted laser beam pattern showed a broadening, which increased with an increase in particle volume fraction. This behavior appeared more remarkable in particles with smaller diameters. The light transmittance of the composite was affected by the particle volume fraction fp and was divided into two characteristic regions according to fp. For fp < 0.01, the light transmittance was slightly affected by the incorporation of the particles, while the light transmittance of the composite with fp > 0.01 was strongly affected by fp and size of the glass particle dp. The effects of fp and dp on the light transmittance are explained by the introduction of a normalized total surface area 〈 S〉 A guideline to obtain higher light transmittance of the composite is discussed based on the parameter 〈S 〉.

scholarly journals Wavelength Dependent Haze of Transparent Glass-Particle Filled Poly(Methyl Methacrylate) Composites

ISRN Optics ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Wolfgang Wildner ◽  
Dietmar Drummer
Keyword(s):  
Refractive Index ◽  
Methyl Methacrylate ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Glass Particle ◽  
Light Transmittance ◽  
Base Line ◽  
Particle Volume ◽  
Poly Methyl Methacrylate ◽  
Refractive Index Difference

Glass particles as filler were incorporated in a poly(methyl methacrylate) matrix. The refractive indexes of both materials match at a wavelength of about 400 nm. The effect of particle volume fraction on the light transmittance and light scattering (haze) in dependence of the refractive index difference was studied. The curve shape of the haze in dependence of the wavelength is comparable to that of the refractive index difference, but the base line of the haze increases with the filling grade. This indicates that there are other scattering or absorbing mechanisms, like defects in the filler binding.

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.

scholarly journals Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids

2015 ◽  
Vol 19 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Jahar Sarkar
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Particle Volume ◽  
Transcritical Carbon Dioxide ◽  
The Given ◽  
Theoretical Analyses

The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction) are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

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