G2O use graphene to coat membranes from existing manufacturers. The coating greatly increases both flux and resistance to fouling
- Fouling of nano/ultrafiltration membranes in oil/water separation is a longstanding issue and a major economic barrier for their wide application. Currently reported membranes typically show severe fouling, resulting from the strong adhesion of oil on membrane surface and/or oil penetration inside the membranes. This greatly degrades their performance and shortens service lifetime. G2O uses graphene oxide (GO) for the fabrication of fully-recoverable membranes for high flux, antifouling oil/water separation via function and structure mimicking of fish scales.
The ultrathin, amphiphilic, water-locking GO coating mimics the thin mucus layer covering fish scales, while combination of corrugated GO flakes and intrinsic roughness of the porous supports successfully reproduces the hierarchical roughness of fish scales. Cyclic membrane performance evaluation tests reveale ~100% membrane recovery by facile surface water flushing, establishing their excellent easy-to-recover capability.
Applying the G2O coating gives membranes a unique combination of high flux rates 100 to 1000 times greater than current ultrafiltration membranes.
The membranes can recover from fouling without the need for chemicals and the pore sizes can be tuned to specific applications such as water desalination, oil/water separation, storm water treatment and industrial waste water recovery.
Initial water flux can be as high as 4400 L/m2.h.bar with excellent superoleophobicity. The membrane can be easily recovered without loss of initial water flux.
- G2O’s patented graphene technology acts as a functional coating for modifying the surface properties of existing filter media resulting in
- Higher pure water flux;
- High fouling resistance;
- Excellent mechanical strength;
- High chemical stability;
- Good thermal stability;
- Low cost
Membranes with different coating thickness can be easily fabricated via a one-time filtration process.
In the G2O oil/water separation process, water preferentially permeates through the GO coated membranes, forming numerous water pockets inside the structure, which serve as a repulsive support for oil droplets.
The hydrophilic GO coating helps trap the water and reduces the effective permeation pore size, introducing additional nano-scaled roughness for smaller oil droplets repulsion. Oil droplets are repelled to the membrane surface and accumulate to form bigger droplets. Then, the oil is released from the super-oleophobic GO membrane surface and floats on top of the oil/water mixture.