Inge Mühlbacher

UV-induced modulation of tribological characteristics: Elastomeric materials featuring controlled anisotropic friction properties

The design of tribologically optimized structures has gained importance in various fields of elastomeric applications ranging from the health care sector to the automotive industry. While many attempts towards improved surface characteristics have been made in recent years, this contribution highlights a new innovative two-step surface modification strategy for enhanced friction properties. Using versatile thiol-ene chemistry, tailored surface structures are architected by means of spatially controlled immobilization of micro-scaled inorganic particles onto natural rubber materials. The chemical composition of the surface was monitored prior to and after its functionalization by XPS, FTIR, zeta potential and contact angle measurements. Physical transformation was analyzed through optical, scanning electron and confocal microscopy in order to gauge surface topology and roughness whilst tribological studies were performed to characterize the friction properties in two dimensions. Upon flood UV exposure, ran...

The influence of surface modification on the electrical properties of silicon carbide flakes

Field grading materials with nonlinear behaviour are used in many high voltage applications to avoid any stress concentration that can deteriorate the material performance. In the present work, the current-voltage characteristics of surface functionalized silicon carbide (SiC) flakes were studied and compared to untreated particles. The nonlinear behavior of SiC flakes can be described by transport mechanisms at the grain contact, which can be modeled by Schottky-like barriers. The influence of the organic surface layer on the conduction mechanisms and the corresponding electrical properties were evaluated. In addition, physico-chemical analysis, including X-ray photoelectron spectroscopy (XPS), optical microscopy and zeta-potential measurements were accomplished in order to analyze the surface properties of the SiC flakes, prior to and after surface modification.