Wu Shuwang, Liang Zhenyu, Li Yupeng, Chay Sarah, He Zhiyuan, Tan Sicong, Wang Jianjun, Zhu Xinyuan, He Ximin
Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA.
School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
Adv Sci (Weinh). 2022 May;9(14):e2105986. doi: 10.1002/advs.202105986. Epub 2022 Mar 11.
Icing and frosting on transparent surfaces compromise visibility on various optical equipment and transparent infrastructures. It remains challenging to fabricate energy-saving coatings for harvesting solar energy while maintaining high transparency. Here, transparent, photothermic, and icephobic composite surfaces composed of photothermal nanomaterials and polyelectrolytes via layer-by-layer assembly are designed and constructed. The positively-charged polypyrrole nanoparticles and negatively-charged poly(acrylic acid) are assembled as exemplary materials via electrostatic attractions. The optically transparent photothermal coatings are successfully fabricated and exhibited photothermal capabilities and light-transmittance performance. Among the various coatings applied, the seven-bilayer coating can increase the temperature by 35 °C under 1.9-sun illumination, maintaining high transmittance (>60%) of visible light. With sunlight illumination at subzero temperatures (> -35 °C), the coatings show pronounced capabilities to inhibit freezing, melt accumulated frost, and decrease ice adhesion. Precisely, the icephobic surfaces remain free of frost at -35 °C as long as sunlight illumination is present; the accumulated frost melts rapidly within 300 s. The ice adhesion strength decreases to ≈0 kPa as the melted water acts as a lubricant. Furthermore, the negatively-charged graphene oxide and positively-charged poly(diallyldimethylammonium chloride) show their material diversity applicable in the coating fabrication.
透明表面上的结冰和结霜会影响各种光学设备和透明基础设施的能见度。在保持高透明度的同时制造用于收集太阳能的节能涂层仍然具有挑战性。在此，通过逐层组装由光热纳米材料和聚电解质组成的透明、光热和憎冰复合表面被设计和构建。带正电的聚吡咯纳米颗粒和带负电的聚丙烯酸通过静电引力作为示例材料进行组装。成功制备了光学透明的光热涂层，并展示了光热性能和透光性能。在所应用的各种涂层中，七层涂层在1.9倍太阳光照射下可使温度升高35°C，同时保持可见光的高透射率（>60%）。在零下温度（>-35°C）下进行阳光照射时，涂层显示出显著的抑制结冰、融化积聚的霜以及降低冰附着力 的能力。确切地说，只要有阳光照射，憎冰表面在-35°C时就不会结霜；积聚的霜在300秒内迅速融化。由于融化的水起到润滑剂的作用，冰附着力强度降低至约0 kPa。此外，带负电的氧化石墨烯和带正电的聚二烯丙基二甲基氯化铵显示出它们在涂层制造中的材料多样性。
