1 SUPPORTING INFORMATION In situ sol-gel obtained silica-rubber nanocomposites: influence of the filler precursors on the improvement of the mechanical properties. Laura Wahba *1,2 , Massimiliano D’Arienzo 1 , Raffaella Donetti 3 , Thomas Hanel 3 , Franca Morazzoni 1 , Roberto Scotti 1 , Luciano Tadiello 1 1 Dip. Scienze dei Materiali, INSTM, University of Milano-Bicocca, Via R. Cozzi 53, 20125 Milano, Italy. 2 Corimav Pirelli, Via R. Cozzi 53, 20125 Milano, Italy. 3 Pirelli Tyre SpA, Viale Sarca, 222, 20126 Milano, Italy. AUTHOR EMAIL ADDRESS: laura.wahba@mater.unimib.it Electronic Supplementary Material (ESI) for RSC Advances This journal is © The Royal Society of Chemistry 2013