Orientational Behavior of Ellipsoidal Silica-Coated Hematite Nanoparticles Integrated within an Elastomeric Matrix and its Mechanical Reinforcement

The mechanical and orientational properties of IOENs consisting of integrated ellipsoidal SCH spindle-type nanoparticles within an elastomeric matrix are reported. The influence of the SCH surface chemistry, leading either to dispersed nanoparticles or crosslinked nanoparticles within the surrounding elastomeric matrix, is studied by mechanical uniaxial deformation (stress-strain) and SAXS measurements under stress. Without surface modifications, the SCH nanoparticles act as defects, and the Young's modulus of the elastomeric matrix remains unmodified. Surface-modified SCH nanoparticles acting as cross-linkers increase Young's modulus by a factor 1.2. SAXS measurements demonstrate that the integrated ellipsoidal nanoparticles orient upon a deformation larger than 50% independently of the specific integration strategy.