Effects of hydrostatic pressure on boundary spreading in sedimentation velocity experiments

✍ Scribed by Billick, Irwin H.

• Publisher: John Wiley and Sons
• Year: 1962
• Weight: 485 KB
• Volume: 62
• Category: Article
• ISSN: 0022-3832
• DOI: 10.1002/pol.1962.1206217313

✦ Synopsis

Abstract

The effects of hydrostatic pressure on boundary spreading in sedimentation velocity experiments have been investigated, both theoretically and on a sample of polystyrene. A series of equations is given for obtaining the integral and differential distribution of sedimentation coefficients when pressure effects are present. These equations were derived on the basis of Fujita's mathematical treatment of the sedimentation of a monodispersed, pressure‐dependent system when diffusion and concentration effects are absent. Using these equations, distributions of sedimentation coefficients are calculated for a sample of polymer with a low polydispersity. The results obtained are compared with those obtained when pressure effects are neglected. The major change is a shift of the curve to higher sedimentation coefficient values, with a slight broadening of the distribution. However, it was found that the ratio of the weight‐average to number‐average molecular weight does not change appreciably.