Formulating Multiphase Medium Anti-wetting States in an Air–Water–Oil System: Engineering Defects for Interface Chemical Evolutions

Abstract

Studies which regulate macroscopic wetting states on determined surfaces in multiphase media are of far-reaching significance but are still in the preliminary stage. Herein, inspired by the wettability subassembly of fish scales, Namib desert beetle shell, and lotus leaf upper side, interfaces in the air–water–oil system are programmed by defect engineering to tailor the anti-wetting evolution from double to triple liquid repellency states. By controlling the visible light irradiation and plasma treatment, surface oxygen vacancies on Cu x O@TiO2 nanowires (NWs) can be healed or reconstructed. The original membrane or the membrane after plasma treatment possesses abundant surface oxygen vacancies, and the homogeneous hydrophilic membrane shows only double anti-wetting states in the water–oil system. By the unsaturated visible light irradiation time, the surface oxygen vacancy partially healed, the heterogeneous hydrophilic–hydrophobic components occupied the membrane surface, and the anti-wetting state finally changed from double to triple in the air–water–oil system. After the illumination time reaches saturation, it promotes the healing of all surface oxygen vacancies, and the membrane surface only contains uniform hydrophobic components and only maintains double anti-wetting state in the air–oil system. The mechanism of the triple anti-wetting state on a heterogeneous surface is expounded by establishing a wetting model. The wetting state and the adhesion state of the Cu x O@TiO2 NW membrane show regional specificity by controlling the illumination time and region. The underwater oil droplets exhibit the “non-adhesive” and “adhesive” state in a region with unsaturated irradiation time or in an unirradiated region, respectively. Underwater oil droplet manipulation can be accomplished easily based on switchable wettability and adhesion. Current studies reveal that defect engineering can be extended to anti-wetting evolution in the air–water–oil system. Constructing an anti-wetting interface by heterogeneous components provides reference for designing the novel anti-wetting interface.

Interfacial engineering of Cu–Fe2O3 nanotube arrays with built-in electric field and oxygen vacancies for boosting the electrocatalytic reduction of nitrates

“…2c) showed three peaks centered at 530.2, 531.4 and 532.6 eV, corresponding to lattice oxygen (O L ), oxygen vacancies (O V ) and hydroxyl groups (O H ), respectively. 50 The area ratios of the O V peak relative to the total area of the O L , O V and O H peaks [SO V /(SO L + SO V + SO H )] were 11.12% and 34.99% for CuO-Fe 2 O 3 and Cu–Fe 2 O 3 -60, respectively. The larger area percentage at ∼531.4 eV in the Cu–Fe 2 O 3 -60 spectrum indicates that the concentration of OVs in Cu–Fe 2 O 3 -60 was much higher than that in CuO-Fe 2 O 3 due to the electroreduction treatment.…”

Effect of Nano-TiO2 Composite on the Fertilization and Fruit-Setting of Litchi

“…The nTiO 2 composite reagent improved the adhesion of the monomer. Through a simulated wiper experiment [ 69 , 70 ], an analysis experiment was developed to explore the adhesion of nTiO 2 . At the bud stage, pistil and stamens were sprayed with nTiO 2 compound reagent ( Figure 6 A,B) and washed with simulated rainwater ( Figure 6 C).…”

Highly Hydrophobic All-Biomass Aerogels with Advanced Oil Absorption and Recyclability

“…There are several types of methods to deal with oil spills on the sea surface, such as physical methods, 3,4 chemical methods, and biological methods. 5,6 At present, the most commonly used one is the physical adsorption method. 4,7,8 The physical adsorption method relies on the use of oil-absorbing materials to achieve the adsorption of oil and is the most effective and cost-effective method for tackling oil pollution.…”