Facile fabrication of oriented polyethylene terephthalate foams as novel solar interfacial vapor generator from waste bottles

Abstract

The massive arbitrarily discarded waste of polyethylene terephthalate (PET) bottles become a major environmental pollution source for soils and oceans. Using these waste products to acquire purified water has great significance. We developed a novel strategy of inducing crystallization coupled with solvent exchanging to obtain oriented PET/carbon nanotubes (CNT) foams from waste PET bottles and to fabricate solar interfacial vapor generators (SIVGs). The obtained PET/CNT foams had low densities of 0.18 g/cm3 and high specific strength with compressive stress of 1.8 MPa. The PET/CNT foams generated excellent capillary action that the water delivering rate reached 93.60 kg/m2 h. In addition, the oriented PET foams demonstrated a promising thermal concentration effect that its surface temperature reached 132.8°C. It could evaporate up to 0.82 kg/m2 h under the illumination of 1 sun. Meanwhile, the foams with CNT clusters dispersion also exhibited excellent electrical resistance of 3.57 × 103 Ω m with a low percolation threshold of 0.5 wt.% CNT. This work provides a novel strategy of manufacturing PET SIVG. The key aspect of this work is the significant increase in the surface temperature and the conductivity of PET SIVG compared with other polymer‐based SIVGs, highlighting its novelty and importance.