Facile Preparation of Ag-Coated Superhydrophobic/Superoleophilic Mesh for Efficient Oil/Water Separation with Excellent Corrosion Resistance.

We present the facile preparation of a superhydrophobic-oleophilic stainless steel mesh with excellent oil/water separation efficiency and resistance to corrosion through hydrofluoric (HF) acid etching, Ag nanoparticle coating, and stearic acid modification, to construct a superhydrophobic micro/nanohierarchical structure. The surface of the treated mesh exhibits superhydrophobicity, with a water contact angle of 152°, and superoleophilicity, with an oil contact angle of 0°. The effects of variation in the HF etching time and Ag nanoparticle coating on surface wettability were explored. The treated mesh demonstrated a very high separation efficiency, as high as 98% for the optimal preparation, on a series of oil/water mixtures. The durability of the treated mesh was tested by repeated separation of kerosene/water mixtures, with the separation efficiency remaining higher than 97% after 40 cycles. In addition, the mesh exhibited an excellent chemical resistance to both acidic and alkaline conditions, with good wearing in hot water. The improved superhydrophobic-oleophilic mesh represents a feasible and realistic oil/water separation methodology even under harsh conditions, and it could have wide application in industrial processes.

High Internal Phase Emulsions Synergistically Stabilized by Sodium Carboxymethyl Cellulose and Palm Kernel Oil Ethoxylates as an Essential Oil Delivery System.

High internal phase emulsions (HIPEs) with an internal phase fraction of 84 vol % were prepared using carboxymethyl cellulose (CMC) and palm kernel oil ethoxylates (SOE-N-60) as a dual emulsifier. Effects of the oil-phase volume fraction, CMC concentration, and SOE-N-60 concentration on oil-in-water HIPEs stability were systematically studied by a Mastersizer 2000 instrument, Lx POL polarizing microscope, rheometer, etc. The bioavailability of tea tree oil can be effectively protected using HIPEs as a delivery system. The experimental results showed that, with the increase of the concentrations of CMC and SOE-N-60, the droplet size of HIPEs gradually decreases and the HIPEs showed good static stability. In addition, it was observed by scanning electron microscopy that the polyHIPEs materials using HIPEs stabilized by different SOE-N-60 and CMC concentrations as templates had different structures. Moreover, the synergism between CMC and SOE-N-60 surfactants plays a significant role in the preparation and stability of HIPEs.

Preparation and Property of Perfluoropolyether Emulsions.

Perfluoropolyether (PFPE) glycerol emulsions were prepared. Three different green surfactants (AES (sodium laureth sulfate), APG (alkyl polyglycoside), and SDS (sodium dodecyl sulfate)) were chosen to emulsify the PFPE. Their properties and performance in shampoo were also investigated. Centrifuge stability measurements show that three PFPE emulsions have good stability. They are stable for 60 min when the centrifugal speed is 6000 r/min. In addition, a change of droplet size was observed with time. Moreover, its rheological properties and application performance was studied. The AES emulsion was the most stable emulsion and it was found to improve the slip and lubricity performance of the cotton, so it has potential applications in shampoo.