Fabrication of solar-reflective, hydrophobic polymer materials with excellent cooling and anti-icing properties through selective etching

Abstract Polymeric cool roofing materials have been concerned all along for their promising applications in energy-saving fields. Simultaneously, anti-icing property is another significant consideration for roofing materials. Herein, porous surfaces were constructed through immersing poly(methyl methacrylate) (PMMA)/chlorinated polyethylene (CPE) blending sheets in cyclohexane/methylbenzene/acetone (90/10/10) mixed solvent to selectively etch some components, and their cooling and anti-icing properties were investigated. Both solar reflectance (Rsol) and thermal emissivity (eT) at atmospheric window (8-13 µm) of porous sample with 30% CPE (Rsol = 93.7%, eT = 87.1%) were higher than those of pure PMMA (Rsol = 13.0%, eT = 86.4%). The porous sample with 30% CPE as a simulated roof possessed the best cooling performance from cooling test: its final temperature was only 25.3 oC after 1 h solar radiation, 27.1 oC lower than that of pure PMMA. Moreover, the porous sample with 30% CPE exhibited very hydrophobic and good anti-icing properties. The freezing point and the freezing time of water on the hydrophobic surface were -24.4 oC and 568 s, 7.2 oC lower and 452 s longer than those of water on the surface of pure PMMA, respectively. We believe that this solar-reflective and anti-icing porous material has potential application for the next-generation roofing material.