Rheo-Optiics for Multicomponent Liquids

1991 ◽  
Vol 248 ◽  
Author(s):  
G. Fuller ◽  
J. van Egmond ◽  
J. Zawada ◽  
L. Archer
Keyword(s):  
Light Scattering ◽  
Structure Factor ◽  
Uniaxial Extension ◽  
Chemical Species ◽  
Polymer Melt ◽  
Orientation Distribution ◽  
Quantitative Information ◽  
Dioctyl Phthalate ◽  
Multicomponent Systems ◽  
Relaxation Dynamics

AbstractThe application of techniques in optical rheometry for the study of multicomponent systems is reviewed. Small angle light scattering (SALS) patterns are related to the structure of concentration fluctuations with length scales of the order of the wavelength of light. Scattering techniques such as SALS and scattering dichroism have been applied to monitor the transient evolution of anisotropic concentration fluctuation enhancement during simple shear induced phase separation in a semi-dilute solution of polystyrene (PS) in dioctyl phthalate(DOP). Furthermore, the Onuki- Doi theory relating scattering dichroism and structure factor has been used to verify the consistency between scattering dichroism and anisotropy in structure factor. Infrared polarimetry is a useful technique in probing the transient microstructural orientation of individual chemical species in multicomponent systems. The simultaneous measurement of intrinsic infrared dichroism and birefringence is particularly effective and has been employed to monitor component relaxation dynamics in miscible blends of poly(ethylene oxide) and poly(methyl methacrylate). Polarization Modulated Laser Raman Scattering (PMLRS) has been successfully employed to study the orientation dynamics of a polymer melt subjected to transient uniaxial extension. PMLRS provides quantitative information about the time evolution of both the second and fourth moments of the orientation distribution function of molecular segments.

Characterisation of an Industrial Polymer Melt Through Either Uniaxial Extension or Exponential Shear Data: An Application of the Pom-Pom Model

2003 ◽  
Vol 13 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Suneel ◽  
Richard S. Graham ◽  
Tom C.B. McLeish
Keyword(s):  
Strain Hardening ◽  
Simple Shear ◽  
Linear Response ◽  
Polymer Melts ◽  
Molecular Model ◽  
Uniaxial Extension ◽  
Polymer Melt ◽  
Non Linear ◽  
Ldpe Melt ◽  
Made In

Abstract We present new non-linear data in extension and two different shear histories. These data are used to compare the effectiveness of using exponential shear data and uniaxial extension data to characterise the non-linear response of an industrial LDPE melt with the pom-pom molecular model. We conclude that extension and exponential shear both allow good predictions to be made in simple shear. However, the characterisation spectrum obtained from exponential shear data fails to predict the correct degree of strain hardening at low extension rates. From this study we are able to suggest circumstances under which exponential shear provides a useful characterisation of branched polymer melts.

Some Effects on Light Scattering Intensity and Red Blood Cell Size Distribution Histograms Due to Sphering

1988 ◽  
Vol 25 (6) ◽  
pp. 673-679 ◽  
Author(s):  
P C Bartels ◽  
P W Helleman ◽  
A F M Roijers ◽  
J B J Soons
Keyword(s):  
Light Scattering ◽  
Blood Cell ◽  
Size Distribution ◽  
Red Blood Cell ◽  
Signal To Noise Ratio ◽  
Quantitative Information ◽  
Cell Size Distribution ◽  
Scattering Intensity ◽  
Distribution Ranges ◽  
Light Scattering Intensity

At present most haematology blood cell analysers routinely provide red blood cell (RBC) size distribution histograms. Sophisticated improvements of the instruments have re-awakened interest in the study of size histograms. The quantitative information derived from the histograms may be applied more fruitfully if insight is available, with respect to some essential principles of sizing technology and methods for treatment of RBCs before measurement. In this study the consequences of sphering RBCs are investigated in relation to the generation of size distribution histograms by means of methods based on light scattering intensity (LSI). Sphering of RBCs results in considerably narrower histograms than unsphered RBCs. The overall signal to noise ratio increases and there is a broader gap between large platelets and microcytic RBCs. Narrower size distribution ranges will enable closer modes to be separated. Compared to unsphered RBCs, microcytic sphered RBCs yield increased LSI whereas macrocytic sphered RBCs yield decreased LSI.

Dynamic structure factor in a bidisperse polymer melt

1995 ◽  
Vol 103 (4) ◽  
pp. 1641-1649 ◽  
Author(s):  
Jeffrey D. Wilson ◽  
Roger F. Loring
Keyword(s):  
Structure Factor ◽  
Polymer Melt ◽  
Dynamic Structure ◽  
Dynamic Structure Factor
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