UConn researchers use additive manufacturing technology to rethink desalination membranes

September 20, 2018 | Case Study

Lux recently interviewed Professor Jeffrey McCutcheon at the University of Connecticut about his recent work in membrane technology. Jeff's team has developed a new membrane manufacturing process for reverse osmosis (RO) membranes. For nearly four decades, RO membranes have been made using interfacial polymerization, where amines and an acid halide undergo condensation to form a polyamide thin-film composite (TFC) layer, typically on top of a polysulfone (PSU) substrate. However, there are three key challenges for membranes produced this way: 

  • Limitation in controlling TFC layer thickness, as this depends on the chemistry
  • The nature of the support or substrate affects the TFC layer, i.e., the roughness or smoothness can impact pore size distribution and hence the membrane's selectivity
  • Fouling due to the thickness or roughness of the surface

The industry has generally found ways around these issues. Common fixes include modifying membrane chemistry, either during the polymerization step or through surface coatings, to make membranes more robust, or investing in pretreatment technologies, which then adds to the overall operational costs of a desalination or brackish water treatment plant.