Pilot-scale production of monodisperse helical silica nanorods: As-synthesized structure and application to rubber compounds

This work discloses a pilot-scale synthesis process allowing the growth of monodispersed silica (SiO 2 ) nanorods, using cost effective and nontoxic reactants only. Water is here the only solvent used, with cetyltrimethylammonium chloride (CTACl) micelles acting as soft templates to control the anisotropic growth of SiO 2 . The abundant, inexpensive, and non-toxic sodium metasilicate precursor is used as a silicon source, allowing the consideration of this synthesis process for the industrial preparation of monodisperse SiO 2 nanorods. We demonstrate the process’ versatility in a pre-industrial 50 L large-scale reactor and display its robustness to repeatedly synthesise anisotropic SiO 2 nanorods with controlled lengths and widths. The added value of those anisotropic SiO 2 structures has been studied in model rubber compounds. We show that SiO 2 nanorods led to a reduction of filler agglomeration, resulting in an increase of the tan δ magnitude, a longer elongation at break and a decrease of the elastic modulus.