It has been expected that superhydrophobic (SHP) surfaces could have potential anti-icing applications due to their excellent water-repellence properties. However, a thorough understanding on the anti-icing performance of such surfaces has never been reported; even systematic characterizations on icing behavior of various surfaces are still rare because of the lack of powerful instrumentations. In this study, we employed the electrochemical anodic oxidation and chemical etching methods to simplify the fabrication procedures for SHP surfaces on the aluminum alloy substrates, aiming at the anti-icing properties of SHP surfaces of various engineering materials. We found that the one-step chemical etching with FeCl3 and HCl as the etchants was the most effective for ideal SHP surfaces with a large contact angle (CA, 159.1°) and a small contact angle hysteresis (CAH, 4.0°). To systematically investigate the anti-icing behavior of the prepared SHP surfaces, we designed a robust apparatus with a real-time control system based on the two stage refrigerating method. This system can monitor the humidity, pressure, and temperature during the icing process on the surfaces. We demonstrated that the SHP surfaces exhibited excellent anti-icing properties, i.e., from the room temperature of 16.0 °C, the icing time on SHP surfaces can be postponed from 406s to 676s compared to the normal aluminum alloy surface if the surfaces were put horizontally, and the icing temperature can be decreased from -2.2 °C to -6.1 °C. If such surfaces were tilted, the sprayed water droplets on the normal surfaces iced up at the temperature of -3.9 °C, but bounced off the SHP surface even as the temperature reached as low as -8.0 °C. The present study therefore suggests a general, simple, and low-cost methodology for the promising anti-icing applications in various engineering materials and different fields (e.g., power lines and aircrafts).

Single-stranded RNA aptamers have emerged as novel biosensor tools. However, the immobilization procedure of the aptamer onto a surface generally induces a loss of affinity. To understand this molecular process, we conducted a complete simulation study for the Flavin mononucleotide aptamer for which experimental data are available. Several molecular dynamics simulations (MD) of the Flavin in complex with its RNA aptamer were conducted in solution, linked with six thymidines (T6) and, finally, immobilized on an hexanol-thiol-functionalized gold surface. First, we demonstrated that our MD computations were able to reproduce the experimental solution structure and to provide a meaningful estimation of the Flavin free energy of binding. We also demonstrated that the T6 linkage, by itself, does not generate a perturbation of the Flavin recognition process. From the simulation of the complete biosensor system, we observed that the aptamer stays oriented parallel to the surface at a distance around 36 Å avoiding, this way, interaction with the surface. We evidenced a structural reorganization of the Flavin aptamer binding mode related to the loss of affinity and induced by an anisotropic distribution of sodium cationic densities. This means that ionic diffusion is different between the surface and the aptamer than above this last one. We suggest that these findings might be extrapolated to other nucleic acids systems for the future design of biosensors with higher efficiency and selectivity.

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A shear horizontal surface acoustic wave sensor (SH-SAW) operating at 104 MHz was functionalized with a polypyrrole (PPy) molecularly imprinted polymer (MIP) for selective detection of flumequine (FLU) in aqueous media.

The superhydrophobic coating was obtained from PTFE, DOTL, PDMS and TEOS on aluminum substrate. a–d present SEM images of coatings without PTFE, with 0.6 g, 1.0 g and 0.6 g PTFE after 34 times icing/deicing experiments, respectively.

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Enhanced electrical transport properties are achieved for La, Pb co-doped BiCuSeO, resulting in optimized thermoelectric properties.