Pseudo-potentiostatic electrolysis by potential buffering induced by the oxygen evolution reaction

A new approach is proposed in order to perform electrochemical oxidation of organics by working under galvanostatic conditions with the potential ‘buffered’ by the competing side reaction of oxygen evolution (OER). According to this process the working potential is fixed by the nature of electrode material and is buffered during organics oxidation by the side reaction of OER. This principle has been used for the selective oxidation of some model organic compounds on Ti/IrO₂ anode.     

Elastic modulus of a polymer nanodroplet: theory and experiment

We redevelop a theoretical model that, in conjunction with atomic force microscopy (AFM), can be used as a noninvasive method for determination of the elastic modulus of a polymer nanodroplet residing on a flat, rigid substrate. The model is a continuum theory that combines surface and elasticity theories for prediction of the droplet's elastic modulus, given experimental measurement of its adsorbed height. Utilization of AFM-measured heights for relevant droplets reported in the literature and from our own experiments illustrated the following: the significance of both surface and elasticity effects in determining a polymer droplet's spreading behavior; the extent of a continuum theory's validity as one approaches the nanoscale; and a droplet size effect on the elastic modulus.     

FWM conversion with pump suppression for filterless optical packet switching applications

The use of a Pump-Suppressed Four Wave Mixing PS-FWM wavelength converter in a wavelength conversion and selection switching scheme is examined and demonstrated. The scheme requires a single 2 × 1 Mach Zenhder Interferometer (MZI) and offers substantial pump suppression and efficiency improvement in terms of optical signal-to-noise ratio. Performance measurements on the combination of PS-FWM wavelength converter with an Arrayed Waveguide Grating (AWG) for passive routing, shows the potentially successful use of the scheme in an ultra-fast wavelength routed optical packet switching scheme where the use of optical filters for the separation of the converted signal from the pump is avoided.     

Impact of strain induced by polymer curing in benzocyclobutene embedded semiconductor nanostructures

Polymers such as benzocyclobutene are commonly used as embedding materials for semiconductor nanostructures. During the curing process of the polymer up to 250 °C, a significant impact of strain can be induced on the embedded semiconductor material due to different thermal expansion coefficients. This strain has been revealed by X‐ray diffraction in free‐standing GaAs nanowires grown on a silicon substrate, embedded in a polymer matrix. It will be shown that this strain is released during the X‐ray irradiation if additionally an external static electric field is applied.