Sedimentation Analysis of Polystyrene Macromolecules with Schlieren Optics.

Sedimentation velocity runs were carried out on two standard polystyrene polymers and their 1:1 mixture in an analytical ultracentrifuge as a function of polymer concentration. Schlieren optics was used for the detection and self-developed VelXLS data analysis program was used for the evaluation of sedimentation data. The generated mean molecular weight for the single component polymer solutions using VelXLS program was similar as the values from dynamic light scattering. The molecular weight distributions from VelXLS also matched with the distributions generated by using interference optics and VelXLAI data analysis program. The sedimentation coefficient was observed to have a concentration dependency as the sedimentation coefficient values shifted to lower values as a function of polymer concentration. The relative amount of polymer fractions in a polymer mixture detected by the analysis programs was also compared. VelXLS program led to the computation of better detection of the amount of polymer fractions, thus, indicating the application potential of VelXLS program for the colloid characterization. [ABSTRACT FROM PUBLISHER]