Browse Prior Art Database

Laser Light Scattering Assay of Particulates in Polymer Solutions

IP.com Disclosure Number: IPCOM000053171D
Original Publication Date: 1981-Sep-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Clecak, NJ: AUTHOR [+4]

Abstract

The success of processes utilizing polymer solutions may depend on the absence of significant amounts of particulate matter in these solutions. A quick and reliable method of assaying such solutions has now been found.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 82% of the total text.

Page 1 of 2

Laser Light Scattering Assay of Particulates in Polymer Solutions

The success of processes utilizing polymer solutions may depend on the absence of significant amounts of particulate matter in these solutions. A quick and reliable method of assaying such solutions has now been found.

Laser light focused into a polymer solution will be scattered in all directions by the polymeric material in the sample. By direct observation with a microscope (see the diagram), three distinct categories of scatterer are discernible. Large scatters, having the dimensions of the order of the wavelength of visible light and greater (roughly 0.5 micron or bigger) appear as very bright points of light moving slowly through the laser beam. Intermediate scatterers having dimensions of the order of hundreds of angstroms to several thousands of angstroms appear both as distinct but relatively dim points of light moving rapidly through the laser beam and as particles sufficiently small that they cannot be seen individually, but are detectable as a dynamic speckle pattern in the beam.

Even smaller scatterers are discernible as a background scattering that is greater than that of the solvent alone. The scattering appears as a dim, well- defined stationary streak in the sample and is devoid of dynamic speckle or individual scatterers. It looks like a more intense version of the scattering due solely to the solvent. Different polymer solutions can have very different scattering ``signatures'' a...