注压成型聚丙烯/碳纳米管材料表面的纳米结构和光热除冰/除霜

Nanohairs and Photothermal Deicing/Defrosting on Surface of Injection-compression Molded PP/MWCNTs Composite

采用注射压缩成型(ICM)快速制备表面具有纳米丝状结构的聚丙烯/多壁碳纳米管(PP/MWCNTs)复合材料复制物.结果表明,密集分布的纳米丝使表面呈现超疏水、极低黏附的润湿状态;MWCNTs和纳米丝有效降低了复制物表面的反射率(在300~800 nm波长范围内平均反射率仅为5.5%),促进复制物对太阳光的吸收(在1 sun(1 kW/m^(2))模拟太阳光照射300 s后其表面平均温度从0℃快速升至77.4℃).复制物的这种润湿状态和高效的光热转换性能使其具有良好防冰和除冰/除霜性能.复制物表面上水滴的结冰时间得到明显延长,在1 sun模拟太阳光照射下冰滴可被快速清除.在光热融霜过程中,复制物表面上融霜碎片卷曲成球形融霜水滴,且融霜水滴自发滑移;融霜结束时,复制物表面上的融霜水滴覆盖率仅为7.5%.研究表明,采用ICM快速制备具有良好被动防冰和主动除冰功能的超疏水高分子纳米复合材料表面是可行的.

The polypropylene/multi-walled carbon nanotubes(PP/MWCNTs)composite replicas with densely distributed nanohairs on their surfaces were rapidly prepared by injection-compression molding(ICM).It was demonstrated that the nanohairs endowed the replica surface with superhydrophobicity(a contact angle of 159.2°)and extremely low adhesion(a roll angle of less than 3°).Both the MWCNTs and nanohairs effectively reduced the reflectance on the replica surface(the average reflectivity was only 5.5%in the wavelength range of 300-800 nm)and promoted the replica to absorb sunlight(its average surface temperature was raised from 0℃to 77.4℃under 1 sun illumination for 300 s).Both the wetting state and efficient photothermal conversion endowed the replica with higher anti-icing and deicing/defrosting abilities.The freezing time of water droplet on the replica surface was prolonged significantly and the ice droplet was quickly removed under 1 sun illumination.During photothermal defrosting,the frost fragments curled into spherical melting droplets and melting droplets spontaneously slid on the replica surface.The surface coverage fraction of the melting droplets was only 7.5%at the end of fully defrosting.The results demonstrate that it is feasible to rapidly fabricate superhydrophobic polymer(nano)composite surfaces with higher passive anti-icing and photothermal deicing/defrosting abilities.