Desalination could be an essential solution to the increasing worldwide clean-water shortage problems. A research team from the University of Houston introduced an ultrathin membrane that improves desalination operations by transporting water at eight times higher speed while retaining successful salt blocking improving overall efficiency.
Polyamide membranes are used as filtration elements in reverse osmosis and nanofiltration systems to extract salt together with impurities from both seawater and brackish water sources. When membranes operate they encounter a performance trade off between permeability enhancement that leads to decreased salt selectivity and improved selectivity that causes decreased water permeation.
The research team collaboratively authored by Sayali Shaligram, Rahul Shevate, Siddhartha Paul led by Assistant Professor Devin Shaffer, has engineered a polyamide membrane with a contorted molecular structure. This design increases the free volume within the membrane, enabling faster water transport without compromising salt exclusion. Shaffer reported:
“We have developed a new type of ultrathin polyamide membrane with a unique, contorted structure that creates more open spaces, or enhanced free volume, within the material,”
The findings, published in ACS Applied Materials & Interfaces, suggest that the new membrane could lower energy consumption and operational costs in desalination plants. You can find the research here:
Shaligram, S., Shevate, R., Paul, S., & Shaffer, D. L. (2025). Highly Permselective Contorted Polyamide Desalination Membranes with Enhanced Free Volume Fabricated by mLbL Assembly. ACS Applied Materials & Interfaces, 17(6), 9716–9727. https://doi.org/10.1021/acsami.4c14332
A higher efficiency level in desalination brings a load of advantages to regions facing substantial freshwater shortages. The improved water-permeable membrane design allows desalination processes to become cheaper which creates promising solutions to address increasing demands for freshwater especially in developing countries where financial, material and technological constraints pose a big issue. The decrease in energy expenses related to this technology helps decrease environmental damages created by large-scale desalination facilities.
“These new ultrathin contorted membranes break that trade-off by letting water through much faster without sacrificing salt rejection, making desalination systems more efficient and cost-effective,”
Shaffer said. Challenges however, still remain in scaling up the technology for implementing in real world settings. Future research will focus on durability testing and optimising manufacturing processes to ensure the membrane’s long-term performance under real-world conditions.
Hassan graduated with a Master’s degree in Chemical Engineering from the University of Chester (UK). He currently works as a design engineering consultant for one of the largest engineering firms in the world along with being an associate member of the Institute of Chemical Engineers (IChemE).
