Evaluationof Silica-Coated PCC as New Modified Filler for Papermaking.

Silica-coatedprecipitated calcium carbonate (PCC) prepared by a sol–gelmethod in a previous study, was used, for the first time, as fillerfor papermaking. Three samples of modified PCC, containing 11, 21,and 29 wt % of silica, were prepared. The handsheets produced witha eucalyptuskraft pulp furnish containing the newPCC-based materials showed better paper strength properties than thosewith the unmodified PCC, whereas the structural properties and brightnesswere not affected (for similar filler retention values (ca. 80%)).The results suggest that a thin film of silica coating the calciumcarbonate crystals has a positive impact on the filler-to-fiber-to-fillerbonding. This may open a new possibility to increase the filler amountin the papermaking industry. [ABSTRACT FROM AUTHOR]