More than 300 million people around the world rely on desalinated water for part or all of their daily needs — a demand that will only grow with larger populations and improved standards of living.
Accessing the oceans for drinking water, however, requires desalination technologies that are complicated and expensive.
In the current issue of Science, researchers at the University of Connecticut offer a new approach to manufacturing a key facet of the process — the membranes integral to desalination. Using an additive manufacturing approach that employs electrospraying, UConn scientists were able to create ultra-thin, ultra-smooth polyamide membranes that are less prone to fouling and may require less power to move water through them.
The most commonly used technology for desalination is reverse osmosis, a process in which seawater is forced through a membrane capable of removing salts and many other molecule contaminants. Conventional approaches to making reverse osmosis membranes have not changed in nearly 40 years.
“Today’s membranes for reverse osmosis are not made in a way that allows their properties to be controlled,” says Jeffrey McCutcheon, study author and UConn School of Engineering’s Al Geib Professor of Environmental Engineering Research and Education. “Our approach uses an ‘additive’ technique that allows for control of a membrane’s fundamental properties such as thickness and roughness, which is currently impossible using conventional methods.”
While the use of reverse osmosis continues to rise around the world, many of its drawbacks, which include high energy consumption and a propensity for membranes to foul, continue to plague the industry.
Illustration depicting the process of reverse osmosis. (iStock/Getty Images Plus)The traditional approach to making these membranes is known as interfacial polymerization. This method relies on a self-terminating reaction between an aqueous phase amine and an organic phase acid chloride monomer. The resulting polyamide films — exceedingly thin, highly selective, and permeable to water — became the gold …