Robust, 3D-printed hydratable plastics for effective solar desalination

In this work, hydratable plastics is being introduced as a new class of materials for effective solar desalination for the first time. In the form of highly amorphous regenerated cellulose, the 3D-printed material achieves a high evaporation rate of 3.01 kg m−2 h−1 under 1-sun irradiation through vaporisation enthalpy reduction. In addition, this work demonstrates that evaporation rate saturation at higher irradiation can be overcome by improving rehydration rate through architectural design via 3D-printing. As such, an unprecedented evaporation rate of 7.35 kg m−2 h−1 under concentrated 3-sun irradiation was achieved. More importantly, water molecules are found to be more locally ordered, leading to more hydrogen bonding in the hydrated cellulose than in bulk. It turns out that the weaker cellulose-water hydrogen bonds with longer bond length and higher deviation from non-linearity is the most probable origins for the significant reduction of vaporisation enthalpy. The 3D-printed evaporators also exhibits long-term stability and anti-salt-fouling ability in evaporating saline water due the interconnectivity of the micro and sub-nano water channels. Finally, purified water collected from a handmade device possess high drinkability.