to reduce fouling by selectively channeling the feed towards particular parts of the membrane and membrane material that separate a sub-set of molecules. Other parts could be printed from different materials with different properties that separate a different subset of molecules all in the same sheet. It may also be easier to accommodate surface texturing of the membrane, which current manufacturing methods engage in to produce membranes less apt to clogging.
Additive manufacturing could also address the problems associated with the high pressures used in reverse osmosis, particularly when desalination of the water is necessary: up to 50-80 bar depending on the salt concentration to be removed.
“Current membranes accommodate these [pressures] well,” Patterson told Design News. “I could imagine that 3D printing in the future being printed of material that is more mechanically robust and therefore is less deformed or affected by pressure compared to current materials.”
As with other additive manufacturing applications, rapid prototyping could also be an advantage in terms of speed, efficiency and customization when compared to traditional prototyping. The CASE team’s work found that 3D printing has the capability to produce not only the membrane, but also the spacers and the entire membrane module, which may reduce the overall production time.
In addition, an AM process for membrane creation could make it possible to control the composition of two or more materials across the surface and interface during fabrication, allowing positional variations in physical properties and characteristics such as multiple alternating layers of materials or selective distribution of one material on another to improve the performance of the membrane.
The researchers’ paper, “ Perspective on 3D Printing of Separation Membranes and Comparison to Related Unconventional Fabrication Techniques ,” was published in the February 2017 issue of the Journal of Membrane Science .