Superhydrophobic polymeric foams, with good thermal stability and highrecycling capacity to remove oil from oily wastewater, are highly desirable for current oily wastewater purification. Herein, poly (styrene-acrylic acid 2,2,3,4,4,4-hexafluoro-butyl ester-divinylbenzene) foam with porosity as high as 99.27% has been prepared through high-internal phase emulsions. Therein, poly (cyclotriphosphazene-co-4,4 0 -sulfonyldiphenol) microspheres, and Span80 act as co-emulsifier to stabilize the emulsion system. The as-prepared foams exhibited super hydrophobicity with a water contact angle of 150.3 and thermal stability. Additionally, the oil adsorption capacity of the porous material could reach up to 25.6-53.4 times its mass with accessible and high-recycling capacity. These aforementioned outstanding properties make our superhydrophobic foam hold potential applications in oil/water separation.
Due to ever‐increasing environmental problems caused by oily wastewater, it is necessary to develop methods for separating oil/water mixtures. However, oil‐in‐water and water‐in‐oil emulsions are highly stable due to the action of surfactants, making them enormously difficult to separate. In this study, we report a 3D superhydrophobic/superoleophilic porous material with a microporous structure and strong negative charge via high internal phase emulsion polymerization to overcome these difficulties. The introduction of 10 wt% α‐zirconium phosphate significantly improved the hydrophobicity of the material (water contact angle = 153°) and also endowed the material with a strong negative charge. The material could separate immiscible oil/water mixtures under turbulent condition and high‐ or low‐temperature environments. Driven by gravity, the as‐prepared monolith separated various oil/water mixtures with the separation efficiency exceeding 99.16%. Benefiting from the diametrically‐opposing wettability and interconnected micropore structure, the foam could separate a Span 80‐stabilized water‐in‐oil emulsion. Furthermore, a cationic surfactant‐stabilized oil‐in‐water emulsion was also separated due to strong electrostatic interactions, which destabilized the oil/water interfacial film. Based on these properties, the as‐prepared porous material shows huge potential for complex oily wastewater treatment.
Timely and accurate estimation of the sugarcane planting area is of vital importance to the country's agricultural production and sugar development. In remote sensing crop mapping based on spectral similarity, there will be have a phenomenon of foreign matters with the same spectrum by obtaining an accurate crop reference curve for crop identification, limiting mapping accuracy. In this study, we improved the spectral reconstruction method based on singular value decomposition (SR-SVD). A decision tree model was established based on the similarity of the sugarcane Normalized Difference Vegetation Index (NDVI) time series curve and the fluctuation range of NDVI in different growth periods. Using the Sentinel-2 (Level-2A) image data set to extract sugarcane planting area in two regions of Chongzuo City, Guangxi, China, the overall accuracy was higher than 96%, respectively. The results show that through the spectral similarity and the determination of the threshold fluctuation range, not only high-precision mapping of sugarcane can be achieved, but the problem of "same spectrum with different objects" can also be solved. Therefore, this method can provide accurate information on the sugarcane planting areas and technical support for monitoring the structure of sugarcane planting in the region.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.