Light scattering low angle

Branching in the polymer chain affects the relationship between retention and molecular weight.83 Universal calibration has been used with some success in branched polymers, but there are also pitfalls. Viscosimetry84-91 and other instrumental methods have proved to be useful. A computer simulation of the effects of branching on hydrodynamic volume and the detailed effects observable in GPC is available in the literature.92 93 In copolymer analysis, retention may be different for block and random copolymers, so universal calibration may be difficult. However, a UV-VIS detector, followed by a low-angle light-scattering (LALLS) detector and a differential... 

Figure 13 Low-angle, light-scattering (LALLS) and refractive index (DRI) chromatograms for two xanthan samples. The xanthan samples were supplied by Shell (-...

Low Angle Light Scattering Photometry Static Envelopes. We shall first consider the final scattering envelopes obtained after gelation is complete. The next subsection will be devoted to the kinetic evolution of the scattering envelopes ... 

A Chromatix low-angle light scattering G.P.C. detector was also employed for the determination of the weight average molecular weight (Mw), as well as a sensitive detector, in order to assay absolutely the Mw versus elution volume profile for a series of star-branched polyisoprenes and polybutadienes. The results indicate that under optimum conditions a relatively well defined number of arms can be achieved with DVB linking. 

Determined by size exclusion cii omatography in tetrahydrofuran with low angle light scattering. 

The present study was carried out using a Chromatix KMX-6DC low-angle light scattering photometer (Chromatix, Inc., Sunnyvale, California) interfaced with a 64-channel digital correlator (Chromatix Model 64) which is linked to a DEC LSI-11 data processing system. The excitation source is a 2mW He-Ne laser ( =6328 A). 

Determined by size exclusion chromatography in tetrahydrofuran with low angle light scattering, k To convert Pa-s to P, multiply by 10. 

If a low-angle light scattering instrument is used, P(0) is close to unity and Mw>i can be calculated directly. For a multi-angle light scattering instrument, the mean-square radius of gyration at each elution volume can also be obtained from P(0) ... 

Mindukshev, I.V., Jahatspanian, I.E., Goncharov, N.V., Jenkins, R.O., Krivchenko, A.I. (2005a). A new method for studying platelets, based upon the low-angle light scattering technique. 

Determination of Molecular Weight from Low Angle Light Scattering Measurements... 

---