Separation of binary and ternary oil/water mixtures from a highly hydrophobic metal mesh.

A highly hydrophobic metal mesh has great potential for its application in oil/water separation due to its special wettability. However, most current oil/water separation devices are simple with limited separation capacity. A separation device based on a highly hydrophobic metal mesh was constructed for different types of oil/water mixtures. Experimental results show that the device not only can be used for the continuous separation of binary oil/water mixtures of any density ratios but also can realize the simultaneous separation of heavy oil/water/light oil ternary mixtures. This achievement is meaningful for practical applications, which will gain great interest in the future.

Candle Soot-Based Electrosprayed Superhydrophobic Coatings for Self-Cleaning, Anti-Corrosion and Oil/Water Separation.

The interest in candle soot (CS)-based superhydrophobic coatings has grown rapidly in recent years. Here, a simple and low-cost process has been developed for the fabrication of CS-based superhydrophobic coatings through electrospraying of the composite cocktail solution of CS and polyvinylidene fluoride (PVDF). Results show that the superhydrophobicity of the coating closely relates to the loading amount of CS which results in coatings with different roughnesses. Specifically, increasing the CS amount (not more than 0.4 g) normally enhances the superhydrophobicity of the coating due to higher roughness being presented in the produced microspheres. Further experiments demonstrate that the superhydrophobicity induced in the electrosprayed coating results from the synergistic effect of the cocktail solution and electrospray process, indicating the importance of the coating technique and the solution used. Versatile applications of CS-based superhydrophobic coatings including self-cleaning, anti-corrosion and oil/water separation are demonstrated. The present work provides a convenient method for the fabrication of CS-based superhydrophobic coatings, which is believed to gain great interest in the future.

Evolution of a Superhydrophobic H59 Brass Surface by Using Laser Texturing via Post Thermal Annealing.

To fabricate an industrial and highly efficient super-hydrophobic brass surface, annealed H59 brass samples have here been textured by using a 1064 nm wavelength nanosecond fiber laser. The effects of different laser parameters (such as laser fluence, scanning speed, and repetition frequency), on the translation to super-hydrophobic surfaces, have been of special interest to study. As a result of these studies, hydrophobic properties, with larger water contact angles (WCA), were observed to appear faster than for samples that had not been heat-treated (after an evolution time of 4 days). This wettability transition, as well as the evolution of surface texture and nanograins, were caused by thermal annealing treatments, in combination with laser texturing. At first, the H59 brass samples were annealed in a Muffle furnace at temperatures of 350 °C, 600 °C, and 800 °C. As a result of these treatments, there were rapid formations of coarse surface morphologies, containing particles of both micro/nano-level dimensions, as well as enlarged distances between the laser-induced grooves. A large number of nanograins were formed on the brass metal surfaces, onto which an increased number of exceedingly small nanoparticles were attached. This combination of fine nanoparticles, with a scattered distribution of nanograins, created a hierarchic Lotus leaf-like morphology containing both micro-and nanostructured material (i.e., micro/nanostructured material). Furthermore, the distances between the nano-clusters and the size of nano-grains were observed, analyzed, and strongly coupled to the wettability transition time. Hence, the formation and evolution of functional groups on the brass surfaces were influenced by the micro/nanostructure formations on the surfaces. As a direct consequence, the surface energies became reduced, which affected the speed of the wettability transition-which became enhanced. The micro/nanostructures on the H59 brass surfaces were analyzed by using Field Emission Scanning Electron Microscopy (FESEM). The chemical compositions of these surfaces were characterized by using an Energy Dispersive Analysis System (EDS). In addition to the wettability, the surface energy was thereby analyzed with respect to the different surface micro/nanostructures as well as to the roughness characteristics. This study has provided a facile method (with an experimental proof thereof) by which it is possible to construct textured H59 brass surfaces with tunable wetting behaviors. It is also expected that these results will effectively extend the industrial applications of brass material.

New Insight into Gap Electrospinning: Toward Meter-long Aligned Nanofibers.

Gap electrospinning is a facile technique to produce aligned nanofibers useful for many applications, but its potential has not yet been fully exploited in nature, leading to the fiber length still limited to several tens of centimeters at present. In this work, we report a breakthrough in the production of well-aligned nanofibers with record length and efficiency. Using a suitable poly(vinylidene fluoride) solution and a pair of parallel plates that are substrate-free and negatively connected, we demonstrate the ease of this technique to prepare length-controllable aligned fibers in a wide range (≤125 cm). Because of the crucial roles of both the jet whipping instability that continuously drives the jet to span across the static plates and the negative voltage on the plates that effectively attracts the positively charged jet, the jet can be made to move back and forth over the superlarge gap to form ultralong aligned nanofibers. By introducing a projection method, we also redefine fiber alignment in a broader sense. This work is believed to provide a new insight into the nature of gap electrospinning, which will greatly expand the versatility of this technique to create devices for a myriad of applications.

Protective Effects of Ethanolic Extracts from Artichoke, an Edible Herbal Medicine, against Acute Alcohol-Induced Liver Injury in Mice.

Oxidative stress and inflammation are well-documented pathological factors in alcoholic liver disease (ALD). Artichoke (Cynara scolymus L.) is a healthy food and folk medicine with anti-oxidative and anti-inflammatory properties. This study aimed to evaluate the preventive effects of ethanolic extract from artichoke against acute alcohol-induced liver injury in mice. Male Institute of Cancer Research mice were treated with an ethanolic extract of artichoke (0.4, 0.8, and 1.6 g/kg body weight) by gavage once daily. Up to 40% alcohol (12 mL/kg body weight) was administered orally 1 h after artichoke treatment. All mice were fed for 10 consecutive days. Results showed that artichoke extract significantly prevented elevated levels of aspartate aminotransferase, alanine aminotransferase, triglyceride, total cholesterol, and malondialdehyde. Meanwhile, the decreased levels of superoxide dismutase and glutathione were elevated by artichoke administration. Histopathological examination showed that artichoke attenuated degeneration, inflammatory infiltration and necrosis of hepatocytes. Immunohistochemical analysis revealed that expression levels of toll-like receptor (TLR) 4 and nuclear factor-kappa B (NF-κB) in liver tissues were significantly suppressed by artichoke treatment. Results obtained demonstrated that artichoke extract exhibited significant preventive protective effect against acute alcohol-induced liver injury. This finding is mainly attributed to its ability to attenuate oxidative stress and suppress the TLR4/NF-κB inflammatory pathway. To the best of our knowledge, the underlying mechanisms of artichoke on acute ALD have been rarely reported.

Laser-Induced-Plasma-Assisted Ablation and Metallization on C-Plane Single Crystal Sapphire (c-Al2O3).

Laser-induced-plasma-assisted ablation (LIPAA) is a promising micro-machining method that can fabricate microstructure on hard and transparent double-polished single crystal sapphire (SCS). While ablating, a nanosecond pulse 1064 nm wavelength laser beam travels through the SCS substrate and bombards the copper target lined up behind the substrate, which excites the ablating plasma. When laser fluence rises and is above the machining threshold of copper but below that of SCS, the kinetic energy of the copper plasma generated from the bombardment is mainly determined by the laser fluence, the repetition rate, and the substrate-to-target distance. With a lower repetition rate, SCS becomes metallized and gains conductivity. When micro-machining SCS with a pulsed laser are controlled by properly controlling laser machining parameters, such as laser fluence, repetition rate, and substrate-to-target distance, LIPAA can ablate certain line widths and depths of the microstructure as well as the resistance of SCS. On the contrary, conductivity resistance of metalized sapphire depends on laser parameters and distance in addition to lower repetition rate.

Electrohydrodynamic deposition of polymeric droplets under low-frequency pulsation.

Circularly shaped polymeric droplets with diameter of about 20 µm have been intermittently ejected and deposited in an orderly manner on a collector from a syringe needle by means of near-field, electrohydrodynamic reactions using pulsating voltages at around 2.25 kV. The needle has an inner diameter of 100 µm and was placed 1 mm above a silicon conductor substrate to have location control for droplet depositions. Under low-frequency operation of less than 100 Hz, the deposition frequency of droplets, f(dep), has been observed to be equal to the frequency of the applied driving voltage divided by an integer, N, as small as 1. Furthermore, the diameter of the deposited droplets has been found to be linearly dependent on (Q/f(dep))(1/3), where Q is the polymer solution supply rate at around 30 nL/s. These experimentally observed droplet ejection rules under low-frequency pulsation provide useful design guidelines for controllable deposition of polymer droplets in various potential applications, including electrohydrodynamic printing.