A composite micro/nanostrucutred (MN) surface was designed using poly(vinylidene difluoride) (PVDF) polymer in combination with ZnO materials via heat-pattern-transfer and crystal-growth techniques. The surface, composed of ZnO nanohairs over PVDF microratchets (i.e., ZP-MN), displays excellent antifogging and icing-delay properties. Condensed water droplets can be easily shed from the ZP-MN surface at -5 °C for ∼1600 s via a slight wind or tilting. The droplets do not completely freeze on the ZP-MN surface at -10 °C until ∼7360 s. This investigation offers a way to design a structured surface that possesses anti-icing ability, which is significant because it can be extended to fields such as microdevices, engineering systems, and engines that operate in a cold or humid environment.

A method for rapid quantitative analysis of the content and distribution of short chain branching (SCB) for α‐olefin/ethylene copolymers based on thermally fractionated DSC is presented. Eight commercial polyethylenes, four made with conventional Ziegler‐Natta catalysts and four made with metallocene catalysts, were analyzed by differential scanning calorimetry (DSC), after having been thermally segregated by successive nucleation annealing (SNA). The polyethylenes were also analyzed by temperature rising elution fractionation (TREF) and carbon‐13 nuclear magnetic resonance (13C‐NMR). The SNA‐DSC procedure segregates polyethylenes according to methylene sequence lengths (MSL). The relationship between DSC melting temperature and SCB content was obtained by calibration with linear hydrocarbons; TREF results were not used in the SNA‐DSC calibration. Deconvolution of the SNA‐DSC endotherms yielded estimates of the average SCB contents and SCB distributions. The SCB contents obtained from the SNA‐DSC for linear low density polyethylenes agreed very well with the SCB contents obtained by 13C‐NMR and TREF, and the SCB distributions measured by SNA‐DSC were very similar to those obtained by TREF. The SCB contents obtained by SNA‐DSC for ultra‐low density polyethylenes, made with metallocene catalysts, were about 20% lower than the values obtained by 13C‐NMR; the values obtained by TREF were even lower.

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The photovoltaic performance of axial and radial pin junction GaAs nanocone array solar cells is investigated. Compared with the cylinder nanowire arrays, the nanocone arrays not only improve the whole optical absorption but more importantly enhance the effective absorption (absorption in the depletion region). The enhanced effective absorption is attributed to the downward shift and extension of the absorption region induced by the shrinking top, which dramatically suppresses the absorption loss in the high-doped top region and enhances the absorption in the depletion region. The highest conversion efficiencies for axial and radial GaAs nanocone solar cells are 20.1% and 17.4%, obtained at a slope angle of 5° and 6°, respectively, both of which are much higher than their cylinder nanowire counterparts. The nanocone structures are promising candidates for high-efficiency solar cells.

Photonic spin-orbit interactions (SOI) provide a new design paradigm of functional nanomaterials and nanostructures, and have especially accelerated advances in spin-orbit photonics. The berry phase or the geometric phase, a salient property of SOI, plays a vital role in this process. Thus, the char acterization of photonic SOI processes together with the Berry phase is highly demanded for studies such as the optical spinHall effect, spintovortex conversion, and Rashba effect. Here, a spinselective and phaseresolved near field microscopic method is proposed and experimentally demonstrated for realtime probing and direct visualization of photonic SOI at mesoscale, and a 3D tomographic technique for imaging the spatial evolutions of the optical phases is also properly realized. By analyzing a metallic metasurface as a spin tovortex conversion platform, the abrupt geometric phase and the spatially evolutional dynamic phases are directly measured and intuitively illustrated. This work provides a powerful tool for the study of spin-orbit phenomena in nearfield optics, and can hold the promise for directly exploring the spin dependent surface states in plasmonics and photonic topological insulators.