Surfactant-free emulsion of epoxy resin/sodium alginate for achieving robust underwater superoleophobic coating via a combination of phase separation and biomineralization.

Underwater superoleophobic coatings exhibit promising prospects in the field of oil contamination resistance. However, their poor durability, stemming from the fragile structures and unstable hydrophilicity, greatly restricted their development. In this report, we proposed a novel strategy of combination water-induced phase separation and biomineralization to prepare the robust underwater superoleophobic epoxy resin-calcium alginate (EP-CA) coating by utilizing a surfactant-free emulsion of epoxy resin/sodium alginate (EP/SA). The EP-CA coating not only exhibited excellent adhesion to various substrates, but also had remarkable resistance to the physical/chemical attacks such as abrasion, acid, alkali and salt. It could also protect the substrate (e.g., PET substrate) from the damage of organic solution and the fouling of crude oil. This report provides a new perspective to fabricate robust superhydrophilic coating with a facile way.

Bio-inspired robust superhydrophilic/underwater superoleophobic coating with lubrication, anti-crude oil fouling and anti-corrosion performances.

The crude oil spill accidents cause numerous crude oil contaminations and oily wastewater. Underwater superoleophobic coating has excellent ability to resist crude oil contamination and separate oily wastewater. But it's hard to keep stable performance against the physical or chemical attack. Herein, a robust underwater superoleophobic coating was fabricated by spraying the mixture of polyethyleneimine (PEI) and TiO2 on epoxy resin (E44) surface. Besides the good physical and chemical stability, the coating exhibited better drag reduction, anti-fouling performance and anti-corrosive performance in water compared with the commercially hydrophilic coating. The stainless steel mesh (SSM), coated by the E44/PEI/TiO2 coating, could separate different oil-water emulsions with a high oil rejection greater than 99.7%.

Novel Environmentally Friendly Waterborne Epoxy Coating with Long-Term Antiscaling and Anticorrosion Properties.

Metal pipes in industrial production are exposed to various corrosive ions. The combined action of these ions with oxygen in water causes corrosion and contamination of the metal pipes and equipment. In addition, metallic ions in water react with anions to form scale on the surface of the metal, which significantly reduces the service life of the metal and equipment, resulting in safety hazards. Waterborne coatings have attracted tremendous attention due to the less negative impact on the environment, but their practical applications are severely restricted by poor barrier properties and poor mechanical durability. Herein, the barrier properties of water-based coatings are successfully improved by adding functional slow-release nanofillers, and the fillers also endow the coating with excellent antiscaling properties. A functional slow-release nanofiller (lecithin/SiO2/HEDP) was prepared using HEDP (etidronic acid) as the scale inhibitor active material and SiO2 as the carrier, combined with a phospholipid membrane with slow-release permeability. With the addition of slow-release fillers, compared with the EP coating, the impedance modulus of composite coatings increases about 1 order of magnitude, the scale inhibition rate is as high as 80.7%, and the antiscaling life is double that of the coating without the phospholipid-coated filler. Thus, this study is expected to provide a new perspective for the preparation of new slow-release fillers and high-efficiency scale inhibitor coatings.

Rationally Designed Self-Healing Hydrogel Electrolyte toward a Smart and Sustainable Supercapacitor.

Excellent self-healability and renewability are crucial for the development of wearable/flexible energy-storage devices aiming for advanced personalized electronics. However, realizing low-temperature self-healing and harmless regeneration remains a big challenge for existing wearable/flexible energy-storage devices, which is fundamentally limited by conventional polymeric electrolytes that are intrinsically neither cryo-healable nor renewable. Here, we rationally design a multifunctional polymer electrolyte on the basis of the copolymer of vinylimidazole and hydroxypropyl acrylate, which exhibits all features solving the above-mentioned limitations. A supercapacitor comprising the electrolyte autonomously restores its electrochemical behaviors at temperatures ranging from 25 to -15 °C after multiple mechanical breakings. Interestingly, it is even able to regenerate for 5 cycles through a simple wetting process in the case of malfunction, while maintaining its capacitive properties and excellent self-healability. Our investigation provides a novel insight into designing smart and sustainable energy-storage devices that might be applied to intelligent apparel, electronic skin or flexible robot, and so on.

Remote Manipulation of a Microdroplet in Water by Near-Infrared Laser.

Facile manipulation of a tiny liquid droplet is an important but challenging issue for many miniaturized chemical and biological systems. Here we report that a microdroplet can be readily and remotely manipulated in aqueous environments under ambient conditions. The droplet is encapsulated with photothermal nanoparticles to form a liquid marble, and subsequently irradiated with a near-infrared (NIR) laser. The marble is able to ascend, shuttle, horizontally move, and even suspend in water by simply controlling the laser irradiation. Moreover, filling and draining of the marble can also be conducted on the water surface for the first time. This facile manipulation strategy does not use complicated nanostructures or sophisticated equipment, so it has potential applications for channel-free microfluidics, smart microreators, microengines, microrobots, and so on.