•The initiator efficiency order: N-methyldiethanolamine (MDEA) > triethanolamine (TEA) > 1.4-diazabicyclo[2.2.2]octane (DABCO).•The quantum yield, bleaching rate and saturated exposure for MB/MDEA were 3.31, 2.62 and 2.49 times of those for MB/TEA.•The proton transfer efficiency and molecular migration ability of electron donor determine the initiator system efficiency.•Quantum yield is replaced by a comprehensive evaluation system including quantum yield, bleaching rate and saturated exposure.Photopolymer film has been widely used in optical devices. However, the low initiator efficiency limits its wider development. In this study, Methylene blue (MB)/N-methyldiethanolamine (MDEA) and MB/1,4-diazabicyclo [2.2.2]octane (DABCO) were first adopted as initiator system in photopolymer film and compared their initiator system efficiencies with the common initiator system MB/triethanolamine (TEA) by a self-established single-beam exposure setup. The MB/MDEA showed the highest performance, while the MB/DABCO was the poorest. The quantum yield, bleaching rate and saturated exposure of the MB/MDEA were 3.31 times, 2.62 times and 2.49 times, respectively, higher than those of the MB/TEA. This order of initiator system efficiencies (MB/MDEA > MB/TEA > MB/DABCO) is exactly consistent with the order of proton transfer efficiencies of the electron donors (MDEA > TEA > DABCO). Furthermore, high proton transfer efficiency and excellent migration of electron donors are helpful to improve initiator system efficiency via surface micromorphology analysis.Download high-res image (352KB)Download full-size image

•Tin coatings containing sol particles were prepared in the stable tin (IV) sols.•The nucleation process was significantly different from that in sulfate bath.•Enhanced corrosion resistance and anti-discoloration performance were obtained.Due to the extensive application of tin coatings, the electrodeposition mechanism, corrosion resistance and anti-discoloration performance have attracted attention in the past decades. In this paper, tin coatings containing sol particles were successfully prepared using the stable tin (IV) sols as the plating bath, based on the water-ethanol electrolytes. The particle size of the tin sols was largely in the range between 4 and 10 nm. When the sol contained 0.475 mol L− 1 SnCl4·5H2O (Sol 2), the sol particles were uniformly deposited on tin coatings. The concentration of tin sol had a significant effect on the surface microstructure and preferred orientation of the electrodeposited tin coatings. The differences in nucleation process of the electrodeposition between tin sols and the aqueous acidic sulfate plating bath (sulfate bath) were revealed by electrochemical analysis. Compared with tin coatings deposited from sulfate bath, tin coatings deposited from Sol 2 had enhanced corrosion resistance and anti-discoloration performance.

•Alumina-silica contained zinc coatings are prepared on NdFeB magnets by electro-deposition method.•The alumina-silica sol improves the corrosion resistance and thermal stability of zinc coatings.•The kinetics features of alumina-silica sol particles under electric field are investigated.•The effect of Si:Al molar ratio for the performance of zinc coating is studied.•The zinc coating possesses better protection performance when the Si:Al molar ratio is 1:1.Alumina-silica particles contained zinc coatings on NdFeB are prepared by an in-situ electro-deposition method from alumina-silica sols contained plating bath. Alumina-silica sols with varied Si:Al ratio are prepared through the two step hydrolysis and condensation of aluminium isopropoxide (AIP) and tetraethyl orthosilicate(TEOS) with acid catalyst. As negative potential applied to NdFeB substrates promotes the deposition of zinc, it also causes the increase of hydroxyl ions concentration, which promotes the particle condensation and gel of alumina-silica sols. The effect of alumina-silica sols on the surface morphology, composition and performance of the electro deposited zinc coatings are studied for NdFeB substrate. The results show that the adsorption and gel of alumina-silica particles are along with the electro-deposition of zinc coating. As the Si:Al ratio increases in added sols, there are more alumina particles get embedded during electro-deposition, which affect the surface morphology and uniformity of zinc coating. Electrochemical and mechanical tests demonstrate that the embedded alumina-silica particles in zinc coatings may serve as inhibitors and help to improve the corrosion resistance and mechanical performance of the zinc coatings on NdFeB magnets.

Superhydrophilicity and underwater superoleophobicity are fundamental issues in many applications for special wettable surfaces. In this work, special wetting behaviors were achieved by using an ecologically friendly wet chemical method. The prepared coatings with porous structure present superhydrophilicity and underwater superoleophobicity. The effects of the reaction conditions, such as pH values and conversion duration, on the morphology and wetting behaviors of the prepared coatings were also studied. A wax deposition test based on the cold-finger method was carried out and good performance was displayed. A possible wax prevention mechanism is proposed, which can be calculated from water film theory. The corrosion resistance and stability of the prepared coatings were also measured. The prepared coatings with special wetting behaviors offer significant insight into the design of anti-wax materials in crude oil transition.

•Phytic acid conversion coating was first applied in wax prevention area.•The surface morphology, composition and wetting behaviors were studied.•The conversion coatings present excellent antiwax performance in wax deposition test.•The antiwax mechanism based on water film theory was proposed.Wax deposition is a detrimental problem that happens during the crude oil production and transportation. To inhibit wax deposition, a conversion coating with excellent antiwax property is developed using a quite simple and environmentally friendly method. The surface morphology, composition and wetting behaviors were characterized by SEM, EDS, FTIR and contact angle meter. A possible mechanism of antiwax is proposed, which can be calculated from water film theory. Due to the simple fabrication and excellent performance, this conversion coating is expected to widely apply in petroleum industry.Download high-res image (219KB)Download full-size image

Binary nanoscale interfacial materials are fundamental issues in many applications for smart surfaces. A binary nanoscale interface with binary surface morphology and binary wetting behaviors has been prepared by a facile wet-chemical method. The prepared surface presents superhydrophobicity and high adhesion with the droplet at the same time. The composition, surface morphology, and wetting behaviors of the prepared surface have been systematic studied. The special wetting behaviors can be contributed to the binary nanoscale effect. The stability of the prepared surface was also investigated. As a primary application, a facile device based on the prepared binary nanoscale interface with superhydrophobicity and high adhesion was constructed for microdroplet transportation.

A flower-like CuO/Cu(OH)2 nanorod film on a brass substrate has been synthesized for the first time, with a tunable wetting transition and excellent stability. We devised a facile etching method utilizing an electrolyte containing K2S2O8 and KOH in this study. The growth process and the surface morphology of the flower-like CuO/Cu(OH)2 nanorods are well documented. Moreover, the surface wetting behavior is reversible between superhydrophilic and superhydrophobic. The as-prepared superhydrophilic surface can be converted to superhydrophobic by modification with myristic acid and can be changed back to superhydrophilic after annealing at 200 °C for 6 min. The wetting transition can be cycled more than 30 times and takes less than 10 min per cycle. We also discussed the wetting transition mechanism based on the surface composition analysis and the relevant theoretical model and investigated the abrasion resistance and flush resistance. For the primary application, we propose that a water-drop collecting device based on a large-scale and complex superhydrophobic surface would show an excellent performance.

Wax deposition is a detrimental problem that happens during crude oil production and transportation, which greatly reduces transport efficiency and causes huge economic losses. To avoid wax deposition, a bioinspired composite coating with excellent wax prevention and anticorrosion properties is developed in this study. The prepared coating is composed of three films, including an electrodeposited Zn film for improving corrosion resistance, a phosphating film for constructing fish-scale morphology, and a silicon dioxide film modified by a simple spin-coating method for endowing the surface with superhydrophilicity. Good wax prevention performance has been investigated in a wax deposition test. The surface morphology, composition, wetting behaviors, and stability are systematically studied, and a wax prevention mechanism is proposed, which can be calculated from water film theory. This composite coating strategy which shows excellent properties in both wax prevention and stability is expected to be widely applied in the petroleum industry.

We demonstrate a method for fabricating a Cu1.8S/CuS nanoplate counter electrode (CE) via the alternating current (AC) etching of brass. The photoelectrochemical performance and electrocatalytic properties of Cu1.8S/CuS CE with a η value of 3.22% are much higher than those of Pt and conventional Cu2S CEs. Furthermore, it offers a simple and low cost method for producing CuS counter electrodes in the future.

Reversible surface wetting behavior is a hot topic of research because of the potential engineering applications. In the present work, a hierarchical micro/nanostructure is fabricated on brass by alternate current (AC) etching. The superhydrophilic as-prepared etched brass (EB) turns into superhydrophobic after the modification of stearic acid for 1 min. After annealing at 350 °C for 5 min, the superhydrophobic modified EB surface becomes superhydrophilic again. Furthermore, the annealed EB can restore the superhydrophobicity with the remodification of stearic acid. The wetting transition is realized by stearic acid modification and annealing rapidly in 6 min. The wetting transition mechanism is discussed based on the surface chemical analysis. This method is facile and suitable for the construction of large-scale and complex brass surfaces with tunable wetting behaviors.Keywords: alternating current; brass; reversible transition; superhydrophobic; wetting behavior;

Wax deposition during the production and transportation of crude oil is a global problem in oil industries. Fabrication of underwater self-cleaning materials can provide a new strategy to prohibit wax deposition. In this paper, conversion films on carbon steel with hierarchical micro/nanostructure are fabricated through a novel in situ alternating-current deposition method. The flower-like conversion films are composed of amorphous iron phosphate and present superhydrophilicity in air and superoleophobicity underwater. The conversion films can efficiently prevent the deposition of wax in water-contained crude oil, showing excellent self-cleaning performance. This facile and low-cost fabrication of a self-cleaning film provides a good strategy for underwater–oil prevention.Keywords: alternating current; conversion films; crude oil; self-cleaning; superoleophobic; wax deposition;

•Cu aggregates on brass with micro-structure after alternating current etching.•After the modification, superhydrophobic surface are obtained on the etched brass.•Water adhesion can be controlled on the superhydrophobic surfaces.•All the process is facile and quick with duration within 6 min.Superhydrophobic surfaces have aroused much attention because of their potential engineering applications. In this paper, a facile and quick method is reported to fabricate superhydrophobic surfaces with controllable water adhesion on brass. After alternating current (AC) etching in phosphoric acid solution for 0.5 min to 5 min, copper aggregates on the brass substrate with different micro-structures. After the modification with stearic acid, superhydrophobic surfaces are obtained. And the wettability of superhydrophobic surfaces can be controlled via varying the etching time. This facile and inexpensive technique provides a novel strategy to construct superhydrophobic surfaces with controllable wetting behaviors.