Brief introduction of results
As a clean and abundant renewable energy source, promoting the application of solar energy to various industries is conducive to the transition to a low-carbon economy and helps to solve the growing energy shortage problem. Solar thermal materials convert solar energy into thermal energy through photothermal effect, keep the surface temperature of the equipment above the freezing temperature under cold conditions, melt/delay the formation of frost/ice on the surface of the equipment, is a new method of using solar energy for de-icing, and is expected to solve the problem of ice in the surface area of outdoor equipment. Carbon-based photothermal materials have the advantages of low cost, wide range of light absorption, high photothermal conversion efficiency, and rich material sources, and have great application potential. However, the existing application of carbon-based materials is limited to their inherent black properties, and the research on how to generate more heat in a limited space through surface morphology regulation is not sufficient. In addition, practical industrial applications have high requirements for the mechanical durability and chemical stability of the material, and the surface is often covered with ice, so the existing anti-/de-icing experiments of a single droplet are not sufficient to characterize the anti-/de-icing properties of the material.
In this paper, Professors Wang Hong and Chen Rong of the Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, are the corresponding authors of the paper, and Doctoral student Xie Zhenting is the first author of the paper in the ChemicalEngineering Journal entitled "Photothermaltrap with multi-scale micro-nano hierarchical structure enhances." Lightabsorption and promote photothermal anti-icing/deicing" paper, the study of the use of template-spray method to prepare a photothermal anti-/de-icing material composed of a substrate, carbon-based light absorbing layer and encapsulation layer. Due to the trap effect, the multi-scale micro-nano composite hierarchy can strengthen the light absorption of the material in a limited space, with an average light absorption rate of ~98% in the 200-2000 nm wavelength range, which is also verified by ray tracing simulations and ultraviolet-visible-near-infrared light absorption test results.
At room temperature (Tr=25 °C)/1 sun (100 mW/cm2) light conditions, the average surface temperature can be increased to ~85 °C, and the photothermal conversion efficiency is as high as 61%. Excellent photothermal conversion properties impart photothermal de-icing properties to the material, and after 100 mW/cm2 light for 300 s, the frost/ice covered by the surface can melt and detach from the wall. In addition, anti-icing experiments show that the prepared materials have a lower freezing temperature (-25.20±1.34 °C), a long icing delay time (774.76±114.19s), and a thermodynamic analysis model of the icing process is also established based on the experimental results. Surface friction, water flow impact and solution immersion tests show that the prepared material has excellent mechanical durability and chemical stability. The material preparation method of this study is simple, the mechanical durability is strong, the photothermal resistance/de-icing performance is excellent, and it has great application potential in outdoor equipment.
Illustrated reading
Figure 1. Schematic diagram of preparation process of carbon-based photothermal anti-icing/de-icing materials.
Figure 2. 3D topography of PS, MS, MNS, P@MNS samples
Figure 3. PS, MS, MNS, P@MNS the light absorption properties of samples
Figure 4. Photothermal conversion performance of PS, MS, MNS, P@MNS samples
Figure 5. P@MNS and Al surfaces are anti-icing in sunlight and no light conditions
Figure 6. De-icing performance of P@MNS, PDMS and Al surfaces under 1 solar light
Figure 7. P@MNS mechanical durability and chemical stability testing of samples
brief summary
In this study, a simple, low-cost, easy-to-control template-spray method was used to successfully prepare a photothermal/de-icing material composed of a basal layer, a light absorption layer and an encapsulation layer (P@MNS). Thanks to the combination of multi-scale micro-nano composite hierarchical structure and multi-layer structure, the prepared material has excellent properties. The experimental results show that the material has excellent photothermal conversion, anti-icing and photothermal de-icing performance, and the photothermal conversion efficiency is as high as 61%, and the thermodynamic analysis model of photothermal anti-icing/de-icing materials in the anti-/de-icing process is also proposed. Ray tracing simulation software and ultraviolet-visible-near-infrared light absorption test results are used to clarify the mechanism of enhanced light absorption in micro-nano structures. Friction, water flow impact and solution immersion tests have also shown that the material has excellent mechanical durability and chemical stability. This research work provides new insights into the design of anti-/de-icing materials with high photothermal conversion efficiency.
literature:
https://doi.org/10.1016/j.cej.2022.135025