Superspreading Surface with Hierarchical Porous Structure for Highly Efficient Vapor-Liquid Phase Change Heat Dissipation.

Superspreading surfaces with excellent water transport efficiency are highly desirable for addressing thermal failures through the liquid-vapor phase change of water in electronics thermal management applications. However, the trade-off between capillary pressure and viscous resistance in traditional superspreading surfaces with micro/ nanostructures poses a longstanding challenge in the development of superspreading surfaces with high cooling efficiency in confined spaces. Herein, a heat-treated hierarchical porous enhanced superspreading surface (HTHP) for highly efficient electronic cooling is proposed. Compared with the single porous structures in nanograss, nanosheets, and copper foam, HTHP with hierarchical honeycomb pores effectively resolves the trade-off effect by introducing large vertical through-pores to reduce viscous resistance, and connected small pores to provide sufficient capillary pressure synergistically. HTHP exhibits excellent capillary performance in both horizontal spreading and vertical rising. Despite a thickness of only 0.33 mm, the as-prepared ultrathin vapor chamber (UTVC) fabricated to exploit the superior capillary performance of HTHP achieved effective heat dissipation with outstanding thermal conductivity (12 121 Wm-1K-1), and low thermal resistance (0.1 KW-1) at a power of 5 W. This regulation strategy based on hierarchical honeycomb porous structures is expected to promote the development of high-performance superspreading surfaces with a wide range of applications in thermal management.

Bioinspired Slippery Surfaces for Liquid Manipulation from Tiny Droplet to Bulk Fluid.

Slippery surfaces, which originate in nature with special wettability, have attracted considerable attention in both fundamental research and practical applications in a variety of fields due to their unique characteristics of superlow liquid friction and adhesion. Although research on bioinspired slippery surfaces is still in its infancy, it is a rapidly growing and enormously promising field. Herein, a systematic review of recent progress in bioinspired slippery surfaces, beginning with a brief introduction of several typical creatures with slippery property in nature, is presented. Subsequently,this review gives a detailed discussion on the basic concepts of the wetting, friction, and drag from micro- and macro-aspects and focuses on the underlying slippery mechanism. Next, the state-of-the-art developments in three categories of slippery surfaces of air-trapped, liquid-infused, and liquid-like slippery surfaces, including materials, design principles, and preparation methods, are summarized and the emerging applications are highlighted. Finally, the current challenges and future prospects of various slippery surfaces are addressed.

Superhydrophilic Fe3+ Doped TiO2 Films with Long-Lasting Antifogging Performance.

Based on the superhydrophilicity of titanium dioxide (TiO2) after ultraviolet irradiation, it has a high potential in the application of antifogging. However, a durable superhydrophilic state and a broader photoresponse range are necessary. Considering the enhancement of the photoresponse of TiO2, doping is an effective method to prolong the superhydrophilic state. In this paper, a Fe3+ doped TiO2 film with long-lasting superhydrophilicity and antifogging is prepared by sol-gel method. The experiment and density-functional theory (DFT) calculations are performed to investigate the antifogging performance and the underlying microscopic mechanism of Fe3+ doped TiO2. Antifogging tests demonstrate that 1.0 mol % Fe3+ doping leads to durable antifogging performance which lasts 60 days. The DFT calculations reveal that the Fe3+ doping can both increase the photolysis ability of TiO2 under sunlight exposure and enhance the stability of the hydroxyl adsorbate on TiO2 surface, which are the main reasons for a long-lasting superhydrophilicity of TiO2 after sunlight exposure.

[Effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and quality and fertilizer nitrogen use efficiency].

A field experiment was conducted to study the effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and its quality, plow layer soil inorganic nitrogen (N) contents, and fertilizer N use efficiency. Compared with traditional urea fertilizer, both sulfur- and polymer-coated controlled release urea fertilizers increased the grain yield by 10.4%-16.5%, and the grain protein and starch contents by 5.8%-18.9% and 0.3%-1.4%, respectively. The controlled release urea fertilizers could maintain the topsoil inorganic N contents to meet the N requirement for the wheat, especially during its late growth stage. In the meantime, the fertilizer N use efficiency was improved by 58.2%-101.2%. Polymer-coated urea produced better wheat yield and higher fertilizer N use efficiency, compared with sulfur-coated controlled release urea.