Low-angle laser light scattering

Low-angle laser light scattering

Low-angle laser light scattering or LALLS is an application of light scattering that is particularly useful in conjunction with the technique of Size exclusion chromatography [ The application of size exclusion chromatography equipped with RI and LALLS detectors to study network formation Polymer Bulletin 27, 281-287 (1991) Zoran S, Petrovic and William J. MacKnight] , one of the most powerful and widely-used techniques to study the molecular weight distribution of a polymer.

Typically the eluent of the SEC column is allowed to pass through both a refractive index detector (that gives measures for the concentration in the solution as a function time) and through a laser scattering cell. The scattered intensity is measured as a function of time under a small angle with respect to the laser beam. Under these conditions the laser signal together with the concentration data can easily be translated into a curve that yields both the Mn and the Mw, the molar mass weighted by number and by weight respectively. The combination of those two data gives information on the linearity of the polymer.

The technique is sometimes complemented or combined with viscometry and polystyrene standards are available [ [http://www.sigmaaldrich.com/catalog/search/ProductDetail/FLUKA/03595 standards] ] for validation of the results.

References


Wikimedia Foundation. 2010.

См. также в других словарях:

  • Multiangle light scattering — (MALS) is a technique for determining, independently, the absolute molar mass and the average size of particles in solution, by detecting how they scatter light. Collimated light from a laser source is most often used, in which case the technique …   Wikipedia

  • Dynamic light scattering — Hypothetical Dynamic light scattering of two samples: Larger particles on the top and smaller particle on the bottom Dynamic light scattering (also known as photon correlation spectroscopy or quasi elastic light scattering) is a technique in… …   Wikipedia

  • Static light scattering — is a technique in physical chemistry that measures the intensity of the scattered light to obtain the average molecular weight Mw of a macromolecule like a polymer or a protein. Measurement of the scattering intensity at many angles allows… …   Wikipedia

  • light — light1 lightful, adj. lightfully, adv. /luyt/, n., adj., lighter, lightest, v., lighted or lit, lighting. n. 1. something that makes things visible or affords illumination: All colors depend on light. 2. Physics …   Universalium

  • Light-emitting diode — LED redirects here. For other uses, see LED (disambiguation). Light emitting diode Red, pure green and blue LEDs of the 5mm diffused type Type Passive, optoelectronic Working principle Electr …   Wikipedia

  • Laser — For other uses, see Laser (disambiguation). United States Air Force laser experiment …   Wikipedia

  • Compton scattering — Light–matter interaction Low energy phenomena …   Wikipedia

  • Rayleigh scattering — This article is about the optical phenomenon. For the magnetic phenomenon, see Rayleigh law. For the stochastic distribution, see Rayleigh distribution. For the wireless multipath propagation model, see Rayleigh fading. Rayleigh scattering causes …   Wikipedia

  • Nova (laser) — View down Nova s laser bay between two banks of beamlines. The blue boxes contain the amplifiers and their flashtube pumps , the tubes between the banks of amplifiers are the spatial filters. Nova was a high power laser built at the Lawrence… …   Wikipedia

  • Nova laser — Nova was a high power laser built at the Lawrence Livermore National Laboratory (LLNL) in 1984 which conducted advanced inertial confinement fusion (ICF) experiments until its dismantling in 1999. Nova was the first ICF experiment built with the… …   Wikipedia


Поделиться ссылкой на выделенное

Прямая ссылка:
Нажмите правой клавишей мыши и выберите «Копировать ссылку»