Abstract: | The theory for sedimentation of macromolecular polyelectrolytes in solutions of low-ionic strength has been modified for the case of a supporting low molecular weight electrolyte possessing a partial specific volume close to unity. The final equations simplify greatly, allowing sedimentation data to be plotted in a linear fashion. These data then may be readily extrapolated to infinite dilution, yielding a value, So, simply related to size and shape. From the initial slope of such plots, the net charge on the macro-molecular polyelectrolyte may be determined. It is suggested that tetramethyl-ammonium chloride may prove to be a satisfactory supporting electrolyte for such studies. |