Hangzhou, China – Thermal phase separation has been used by a team of chemists at Zhejiang Sci-Tech University to make a graphene oxide doped porous polyurethane sponge. They suggest that it could have applications in treating water pollution.
Their first step was to create a porous TPU sponge that had excellent hydrophobicity. By modifying the preparation conditions, they managed to create a sponge with a saturated oil absorption capacity of 13.3g of oil per gram of sponge. Absorption equilibrium was achieved within just 20 second.
This sponge was able to selectively absorb a range of different oils and organic solvents from oil/water mixtures. The recovery rate was high, they said.
Next, they looked to increase the sponge’s hydrophobicity and improve its mechanical properties by doping it with 3% graphene oxide. Morphological studies showed that these doped sponges had uniformly distributed nanopores and mocropores, as well as the desired improvements in properties.
These composite sponges were superelastic and had excellent reversible compressibility, they said, along with strength up to 186kPa at 80% strain. This enables oil to be re-absorbed simply by manual extrusion.
The work has been published in the journal ACS Omega.