Additive technology to eliminate bio-fouling in membranes; e.g., desalinization
Physical Sciences : Materials and Compounds
Available for licensing
- Benny Freeman, Ph.D. , Chemical Engineering
- Bryan McCloskey, Ph.D. , Chemical Engineering
- Ho Park, Ph.D. , Hangang University
- Todd Emrick , University of Massachusetts
- Ravindra Revanur , University of Massachusetts
- Kurt Breitenkamp , University of Massachusetts
One of the major roadblocks to widespread use of membranes for water purification is membrane fouling. Fouling occurs when certain impurities in water are deposited on the surface of a membrane or in its internal pore structure. This deposition leads to a dramatic reduction in water flux, which increases the operating costs and decreases membrane lifetime. Therefore, new membrane materials are needed to help reduce foulant adhesion. Most studies have focused increasing membrane hydrophilicity as a method to eliminate fouling, as foulants are mostly organic compounds that have a high binding affinity with hydrophobic surfaces.
Inventors at The University of Texas at Austin have developed a novel deposition technique to coat polydopamine, a highly hydrophilic polymer, onto the surface of commercial reverse osmosis and ultra-filtration membranes. The investigators have shown that polydopamine increases the surface hydrophilicity of the membranes, which leads to a reduction in fouling. This fouling reduction results in higher membrane fluxes when filtering oil-water emulsions.
- One-step, simple modification
- Process can be performed on already formed membrane modules.
- Lab results have shown an increase in membrane flux up to 35% in produced oil water.
- Process is not specific to membrane chemistry; provides ability to modify any membrane, regardless of base membrane material. Polydopamine can deposit on virtually any surface with which it comes into contact.
- Increases the lifetime of a given membrane module by reducing fouling of the membrane surface
- Improved hydrophilicity (high angle of contact)
- Ensures that delamination will not occur for the coating layers currently used in membranes
Polydopamine, a hydrophilic, neutrally-charged polymer, can deposit on virtually any surface with which it comes into contact. Therefore, it has wide potential to be used as an effective anti-fouling coating layer in many membrane water purification applications.
Polydopamine’s structure is also of interest in oxidative (alkaline) environments, where it can be used as an “intermediate ” layer between a hydrophobic membrane and a hydrophilic coating. The hydrophilic layer will show improved adhesion to the membrane support, allowing long-term membrane operation.