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To date, the theoretical studies on dry abrasion on surfaces with microscopic roughness are based on JKR or DMT contact theory. Superhydrophobic nanocomposite coatings with low surface energy and microscopic surface roughness have extremely low real contact area and adhesion to the abrasive when subjected to contact and friction, making the above theories inapplicable. To date, there lack of theoretical studies on the dry abrasion characteristics of superhydrophobic nanocomposite coating surfaces. In response to this problem, a numerical understanding of the frictional force on superhydrophobic nanocomposite coatings is proposed based on Hertz contact theory, and the abrasion mechanisms of superhydrophobic nanocomposite coatings and its influencing factors are analyzed from the perspective of microscopic torque balance. The abrasion process is divided into three stages, and there exists a minimum value of bonding strength between the microstructure on the coating surface and the polymer matrix of the coating that determines whether abrasion will occur. This minimum bonding force is determined by Young's modulus of the polymer matrix, the radius of the microstructure, and the applied load. The conclusions can be a guide for the improvement of the anti-dry-abrasion property of superhydrophobic nanocomposite coatings from the perspective of coating preparation. [ABSTRACT FROM AUTHOR]

We study the optimal sensing condition for periodic gold nanoslits. The intensity sensitivities for various periods, from 400 to 900 nm, were measured. The experimental results show that 500-nm-period array has a maximum bulk sensitivity, three times larger than the sensitivities of 400 and 700 nm periods. The optimal period is attributed to the coincidence of the surface plasmon resonance (SPR) wavelength and lowest imaginary dielectric constant of gold film. The structure reaches a figure of merit of 23.9 and achieves a detection limit of 2.6 × 10-5 refractive index units at 0.2% stability, better than the grating-based SPR sensors using intensity interrogation. [ABSTRACT FROM AUTHOR]

Large phase differences between transverse electric (TE) and transverse magnetic (TM) waves were investigated in plasmonic nanoslit arrays. The phase of the TE wave shifts ahead because of its low propagation constant. On the other hand, the phase of the TM wave is retarded due to the propagation of surface plasmons. The opposite phase shift forms a giant birefringence. Its magnitude was dependent on the width of nanoslits. The birefringence magnitude was ∼1 for 300-nm-wide nanoslits and up to ∼2.7 for 100 nm ones. The spectroscopic measurements indicate that waveplates made of gold nanoslits have large bandwidths. [ABSTRACT FROM AUTHOR]

Inspired by a well-known fact that the magnetic coercivity of a thin film has a strong dependence on its thickness, we have fabricated a 5×60 μm and 30 nm thick cobalt (Co) strip with thickness modulation along its long axis. The modulation period of 700 nm with a depth of 8 nm was prepared by a focused ion beam. From magnetic force microscope images, we observed an induced magnetic anisotropy along the short axis of the strip. By comparing out-of-plane magnetoresistance measurements in two magnetic remnant states, we extracted a positive domain wall resistance of 0.03 Ω, corresponding to 0.14% magnetoresistance (MR) in a Co thin film. [ABSTRACT FROM AUTHOR]

A large-area and periodically patterned nanoporous aluminum grid with controlled pore size was fabricated by poly(ethylene oxide)-assisted self-assembly of polystyrene nanospheres. The grid layer was used as the shadow mask for the creation of nanochannels in a polymeric dielectric layer, as well as the base electrode in a space-charge limited transistor prepared thereafter. A high performance device with poly(3-hexylthiophene) as conducting semiconductor was achieved, yielding a high on-current output of ∼12 mA/cm2 and a high on-off ratio of ∼2 × 104 at a collector voltage of -2.0 V. [ABSTRACT FROM AUTHOR]

We have developed an approach to prepare large array nanostructured thin films using polyethylene oxide assisted self-assembly of polystyrene nanospheres as a template. By tuning the antidot diameter in the cobalt thin films, we found a crossover behavior in the magnetization reversal process. In addition, the effective moment per cobalt atom turns out to drop with growing antidot diameter which effectively increases the surface to bulk volume fraction. Our results suggest a tendency of reduced saturation magnetization in a ferromagnet/normal metal interface, where the mixing of itinerant electrons with ferromagnetic d electrons can give rise to observable effect. [ABSTRACT FROM AUTHOR]