Farmers' adoption behavior of conservation tillage technology: a multidimensional heterogeneity perspective.

Adopting conservation tillage technology can promote sustainable agriculture development. There have been many studies on all farmers' conservation tillage behaviors, but few studies are based on a farmer's multidimensional heterogeneity perspective. Given the background, we conduct an empirical evaluation using micro survey data from 819 households in the middle and upper reaches of the Yellow River Basin. This paper uses the entropy method to classify farm households into three types: economically dominant, resource dominant, and socially dominant. Furthermore, we use the Heckman sample selection model to discuss the factors that affect the adoption of conservation tillage technology by different types of farmers. The results show that land fragmentation degree can inhibit economically dominant farmers conservation tillage technology adoption behavior. Social relations can positively influence resource dominant farmers. The share of non-farm income will positively impact socially dominant farmers. This paper further proposes policy implications, based on the findings that different types of farmers have various factors influencing conservation tillage technology adoption behavior.

Hygro-responsive, Photo-decomposed Superoleophobic/Superhydrophilic Coating for On-Demand Oil-Water Separation.

The superoleophobic/superhydrophilic material has attracted considerable interest due to the incomparable property of it for the oil-water separation. However, it is a challenge to make the prepared surface superoleophobic and superhydrophilic at the same time since the oleophobic surface tends to repel water. Herein, a hygro-responsive superoleophobic/superhydrophilic coating was fabricated by liquid-phase deposition of TiO2 with perfluorooctanoic acid. The wettability of the coating could complete the transformation from superoleophobicity/superhydrophilicity to superhydrophobicity/superoleophilicity, both of which exhibit excellent selective superwettability under the air, underwater, salt, alkali, and acid conditions. The hygro-responsive coating can separate different types of oil-water mixtures, and the separation efficiency could be over 99% using different capillary forces acting on the oil and water phases before and after wettability transformation. Last but not least, long-chain perfluoroalkyl substances on the coating could be decomposed by UV irradiation, which could reduce the harm to the environment and human beings. It is anticipated that the developed superoleophobic/superhydrophilic coating provides a feasible solution for the application of oil-water separation.

Superhydrophilic Al2O3 Particle Layer for Efficient Separation of Oil-in-Water (O/W) and Water-in-Oil (W/O) Emulsions.

The separation of oil-water emulsion using superliquiphobic/philic porous coated materials has attracted considerable attention for dealing with environmental pollution and resource recycling issues. The coatings used may lack adequate surface mechanical and chemical durability. This paper proposes a simple method without other modifications for separating the oil-water emulsion. A porous layer was fabricated by superhydrophilic Al2O3 particles, which could separate oil-water emulsions. The particle layer has the property of underwater superoleophobicity after prewetting. For the oil-in-water (O/W) emulsion separation, a 0.3 µm Al2O3 particle layer was used. This layer had a pore size less than about 1 µm to minimize oil flow and to obtain a purity of oil recovery greater than 99 wt %. For the water-in-oil (W/O) emulsion separation, a 40 µm Al2O3 superhydrophilic particle layer was used. Larger particles were used to provide a more porous surface to facilitate oil flow through the layer, resulting in a purity of water recovery purity greater than 99 wt %.

Multifunctional TiO2-Based Superoleophobic/Superhydrophilic Coating for Oil-Water Separation and Oil Purification.

Materials that possess distinguishable superwettability toward oil and water have aroused widespread attention for their application in oil-water separation. Among them, a superoleophobic/superhydrophilic material is considered as the ideal candidate because of its antioil-fouling and water-wetting behavior; however, the fabrication is a challenge and there has been insufficient attention given to multipurpose applications in treating intricate mixtures. Herein, for the first time, a multifunctional superoleophobic/superhydrophilic coating integrated with a photocatalysis property was fabricated by the combination of polarity component-enhanced fluorosurfactant and titanium dioxide (TiO2) nanoparticles. The coating applied on stainless steel mesh preserves the ability to separate immiscible oil-water mixtures, whereas the coated cotton preserves the ability to separate both surfactant-stabilized oil-in-water and water-in-oil emulsions. Notably, benefiting from the photocatalysis property of titanium dioxide, the coating also can be used in liquid purification. Contaminated oil can be separated and purified by a separation-purification process, during which the oil-soluble contamination is degraded under ultraviolet (UV) irradiation. The multipurpose coating provides an alternative solution for oil-water remediations, which has prospects in intricate liquid treatment in industrial and domestic applications.

Ultraviolet-driven switchable superliquiphobic/superliquiphilic coating for separation of oil-water mixtures and emulsions and water purification.

Materials with switchable wettability by external stimuli are of interest in on-demand oil-water separation. Among these materials, ultraviolet (UV) light-stimuli TiO2-based materials are considered as predominant candidates due to the photoinduced superliquiphilicity of TiO2. Besides the photoinduced superliquiphilic property, the photocatalysis is another important intrinsic property of TiO2 which has applications in liquid purification. Therefore, TiO2-based material with these two properties can achieve both separation of diverse oil-water mixtures and liquid purification. In this study, a substrate-independent, UV-driven switchable superliquiphobic/superliquiphilic coating was developed by a facile one-pot method. The wettability of the coating can be rapidly switched between superhydrophobicity/superoleophilicity and superhydrophilicity/underwater superoleophobicity by UV irradiation and heating process, which can be used for on-demand separation of both immiscible oil-water mixtures and emulsions. Such a coating can also be used for the degradation of soluble contamination in water during UV irradiation due to the photocatalysis property of TiO2. The coating provides an effective solution for both on-demand oil-water separation and water purification, which is of interest in both industrial and domestic applications.

Rapid, ultraviolet-induced, reversibly switchable wettability of superhydrophobic/superhydrophilic surfaces.

Controllable wettability is important for a wide range of applications, including intelligent switching, self-cleaning and oil/water separation. In this work, rapid switching and extreme wettability changes upon ultraviolet (UV) illumination were investigated. TiO2 nanoparticles were modified in solutions of trimethoxy(alkyl)silane, and the suspensions were sprayed on glass substrates. For such samples, the water contact angle (WCA) was shown to transition from a superhydrophobic (WCA ≈ 165°) to a superhydrophilic (WCA ≈ 0°) state within 10 min upon UV illumination and subsequent recovery to superhydrophobicity occurred after heat treatment. It was found that the changes in the trimethoxy(alkyl)silane upon UV illumination can explain the rapid decrease of the WCA from more than 165° to almost 0°. To further investigate the wettability transition, trimethoxy(alkyl)silane and Al2O3 nanoparticles (which are not photocatalytic) were mixed and spray-coated onto the glass substrates as the control samples. Then the unrecoverable change of trimethoxy(alkyl)silane under UV illumination can be confirmed. It was found that the presence of trimethoxy(alkyl)silane in the TiO2-trimethoxy(alkyl)silane coating served to speed up the super-wettability transition time from superhydrophobicity to superhydrophilicity, but also limited the number of wettability recycle times. With this understanding, the effect of the trimethoxy(alkyl)silane concentration on the number of recycle cycles was investigated.