Charge and Size Selective Ion Sieving Desalination Membranes
MXenes are a family of atomically thin, two-dimensional (2D) transition metal carbides (compound composed of carbon and a less electronegative element) and carbonitrides (MxCyNz) with many attractive properties including conductivity and mechanical strength. QEERI's scientist Dr. Khaled Mahmoud, and his colleagues have recently pioneered the research on two-dimensional MXene (Ti3C2Tx) as size/charge selective ion sieving membranes for applications in water desalination/purification. The first ever repot on MXene membranes has been published in collaboration with Drexel University by the American Chemical Society.
A major success indicator for any water treatment membrane is the resistance to biofouling. To validate this and to understand better the health and environmental impacts of the new 2D carbides, QEERI scientists - Kashif Rasool, Mohamed Helal, Adnan Ali and Khaled Mahmoud- have investigated for the first time the antibacterial properties of single- and few-layer Ti3C2Tx MXene flakes in colloidal solution. Ti3C2Tx shows a higher antibacterial efficiency toward both Gram-negative E. coli and Gram-positive B. subtilis compared with graphene oxide (GO), which has been widely reported as an antibacterial agent. Antibacterial mechanism investigation by scanning electron microscopy (SEM), and transmission electron microscopy (TEM) coupled with lactate dehydrogenase (LDH) release assay indicated the damage to the cell membrane which resulted in release of cytoplasmic materials from the bacterial cells. MXenes are expected to be resistant to bio-fouling and offer bactericidal properties. This novel work has been featured recently in ACS Nano.
This work was conducted with the capabilities of QEERI labs at the College of North Atlantic, Qatar. QEERI is grateful to the College of Medicine at Drexel University and to the Central Lab Unit at Qatar University for access to TEM and SEM characterization, respectively.