Haikou, China – Desalination of seawater has the potential to create abundant supplies of drinking water, but it is an energy-intensive process. A team at Hainan University has created an interfacial solar evaporator that uses liquefied-chitin polyurethane foams as the base material that may prove more effective.
Efficient photothermal interface materials are essential if a solar powered photothermal conversion and water evaporation process is to be successful. In the device, polyaniline and polypyrrole convert solar energy into thermal energy, and a hydrogel is generated in situ in the PU foam to reduce the water’s enthalpy of evaporation and speed up its evaporation.
Using liquefied-chitin gives a PU foam that has a low thermal conductivity, reducing the heat loss of the water. The liquefied-chitin PU foam also has antibacterial properties, which may reduce the build-up of bacteria that might affect the efficiency of the photothermal evaporation process.
As a result, high water evaporation rates and photothermal conversion efficiencies could be achieved. The team suggest that the study points the way towards creating a simple way of converting PU foam into efficient solar thermal materials for desalination.
The work has been published in the Journal of Applied Polymer Science.