POLYMER-SUPPORTED REDOX CATALYSTS: DETERMINATION OF APPARENT SURFACE COVERAGE.

In a previous article, the preparation and characterization of new poly(vinyl chloride) (PVC)-supported redox catalyst containing the cyclopentadienyl iron moiety was reported. Polymers with pendant metallocenic groups and with various Fe content were analyzed by spectroscopic techniques and by polarographic and cyclic voltammetry. The active center in the new polymer-supported catalysts is attached as a pendant organometallic moiety in the side groups of the PVC chain. Therefore, the characterization of the surface of this new catalyst is important to obtain information about the relationship between Fe content in the polymer and the 'apparent surface coverage' (ASC) of the aggregates. In these studies the zero point charge (ZPC) was used to evaluate the ASC. It has been shown that the ZPC is related directly to the composition of the samples, and there is experimental evidence that the ZPC measured by electrophoretic migration depends on the surface composition. The method of electrophoretic migration is described. Experimental data are presented which show that the electrophoretic migration method can be used in a catalytic system such as that studied in this report.