Metal-Organic Framework Glass Composites for Sustainable Water Solutions

Access to safe, clean, and adequate water is vital for human sustainability and well-being. Despite water covering 71% of Earth’s surface, hardly 0.03% of its freshwater is directly accessible for human use. Desalination of seawater, while a promising solution to access clean water, is hindered by the removal of scaling ions such as calcium (Ca²⁺) and magnesium (Mg²⁺), damaging equipment and reducing efficiency. Unfortunately, polymeric membranes and ion exchange resins employed in current desalination systems present several drawbacks such as thermal sensitivity, low selectivity, etc. This work introduces a unique hybrid material by functionalizing a metal-organic framework (MOF) glass with a traditional oxide glass. This novel composite material synergistically combines the processability and durability of traditional oxide glass with the adjustable porosity and ion selectivity of MOFs. The resulting hybrid demonstrates very high efficiency in removing Ca²⁺ and Mg²⁺ ions, outperforming existing adsorbents including current commercial standards. To validate its effectiveness, we have tested seawater samples obtained from various locations (Red Sea-Saudi Arabia, Mediterranean Sea-Spain, and Baltic Sea-Denmark), yielding excellent outcomes in seawater softening (removal of Ca2+ and Mg2+ ions) applications. Furthermore, we have developed a self-standing membrane based on the moldability of the hybrid systems, enabling scalable and reliable seawater softening.