Desert sand is one of the most abundant natural resources, its reutilization is of significance and very valuable for the sustainable development of the environment. In this work, to realize the efficient reutilization of desert sand, we developed a facile method to fabricate superhydrophobic sands based on the self-assembly of PTFE nanocoating. The as-prepared sands exhibit simultaneously superhydrophobic and superoleophilic properties with a water contact angle is ∼150° and an oil contact angle is ∼0°. Besides, the applications of the as-prepared functional sands in water storage and oil/water separation were investigated in detail. The results show that the as-prepared sands exhibit good water storage capacity compared with the raw desert sand. Additionally, the as-prepared sand layer used as an adsorbent or filter can efficiently separate both light and heavy oil/water mixtures with a separation efficiency of > 96% and separation flux of > ∼24000 L/m 2 h. This work provides a good alternative for achieving the reutilization of desert sand and other natural resources.
Shumin Liu,Tailong Cai,Xiaoyuan Shen,Erzhuo Huang,Zhe Wang,Qingfeng Sun
Sand as a kind of natural material exists abundantly in desert has not been effectively utilized because of its superhydrophilicity. In this study, the superhydrophobic sand particles were successfully fabricated by structuring mussel-inspired polydopamine and TiO 2 coatings on sand surfaces and subsequent hydrophobic modification with low surface energy material. The water droplets stood on the superhydrophobic sand surfaces with an almost perfect sphere (water contact angle of ~153°), which broke the conventional concept towards the superhydrophilicity of sand. Furthermore, the obtained superhydrophobic sand particles had good water-holding capacity and high thermal stability, which contributed to the storage of water in desert. Meanwhile, the superhydrophobic sand exhibited a multifunctionality including oil/water separation, anti-icing properties and waterproof coating on fiberboards, which widened the application fields of desert sand and provided fast access to sustainable development of environment and natural resource.
Direct particle receiver of the concentrated solar power (CSP) with a supercritical CO 2 (sCO 2 ) Brayton cycle is based on the solid particles to achieve high efficiency at high temperature. Among all kinds of solid particles, desert sand is abundant and cheap, however its solar weighted absorptance and thermal stability remain to be improved. In this work, the dark desert sands were obtained by in-situ coating transition metal oxides via sol-gel combustion process . The thermal stability of the resultant samples was analyzed according to the changes in composition , morphology and optical properties before and after thermal treatment at 800 °C for 200 h. Based on the characterization of UV–Vis–NIR diffuse reflectance spectroscopy , the solar weighted absorptance of each sample was calculated. Compared with the original particles, all of dark desert sands have the improved solar weighted absorptance, and the highest value of 0.8635 belongs to desert sand coated with spinel CuMn 2 O 4 . Moreover, compared to the original desert sand, each dark desert sand has superior thermal stability. In addition, the specific heat of particles was measured at different temperatures, and it is found that the coating has lesser effects on the specific heat of desert sand. The solar weighted absorptance of dark desert sand nearly unchanged after attrition and the coating remained well maintained on the surface of the sample. This work provides a practical and feasible way to enhance the solar weighted absorptance and thermal stability of desert sand, making it possible to apply in sCO 2 CSP.
Xuetao Xu,Ziyun Chen,Xizi Wan,Zhao Wang,Yikai Zhang,Jingxin Meng,Lei Jiang,Shutao Wang
Summary Low-carbon building materials are attracting enormous attention due to the massive energy consumption and carbon emissions from conventional constructions. Existing natural-based building materials are promising for low-carbon constructions but challenging in realizing high mechanical strength for practical applications. Here, inspired by colonial sandcastles, we report the large-scale fabrication of natural-based low-carbon building materials (nLCBMs/±) by a bio-inspired adhesive strategy under low temperature and atmospheric pressure. The as-prepared nLCBMs/± show outstanding compressive strength up to the construction criteria of cement-based materials, hydration-enabled recyclability, and an anti-weathering property. Furthermore, the bio-inspired adhesive strategy is versatile to various grains, such as desert sands, sea sands, concrete slag, coal cinders, and mineral residues. Our finding provides a promising route in accelerating the next-generation construction industry with limited energy consumption and carbon emissions.
危险品化学品经营许可证（带存储）