SILICA PARTICLES STABILIZED BY LONG GRAFTED POLYMER-CHAINS - FROM ELECTROSTATIC TO STERIC REPULSION

Silica particles grafted with long polydimethylsiloxane chains have been prepared. A progressive grafting process was used, allowing transfer of the beads from their initial polar medium to various organic solvents. They are revealed to be model colloids whose properties are driven by the structure of the grafted polymer layer. Depending upon the grafting density, two basic kinds of particles may be distinguished, exhibiting either coulombian or steric interactions. © 1992.