Chicago Future Manufacturing Seminar Series: Ti3C2 MXene Surface Modification and Nanocomposites: Water Purification and Gas Separation

 MXenes are a family of two-dimensional materials composed of transition metal carbides, nitrides, and/or carbonitrides, produced mostly by selectively etching elements from MAX phases. They exhibit excellent electrical conductivity, mechanical strength, and ease of surface functionalization, making them ideal for applications such as gas separation, water purification, energy storage, and sensors. We have investigated the surface modification of Ti3C2 MXene. In one study, a simple one-step carboxylation method reduced the zeta potential of Ti3C2 by 16–18 mV across a pH range of 2.0 to 8.5 and enhanced its stability in the presence of molecular oxygen. The carboxylated Ti3C2 exhibited faster mercury ion uptake and less mercury ion leaching compared to pristine Ti3C2. In another study, surface modification using an aminosilane coupling agent changed the surface charge of Ti3C2 from –35 mV to +25 mV at neutral pH, allowing for the in-situ formation of self-assembled films. We have also studied embedding pristine and modified Ti3C2 into polymers (e.g., Pebax-1657) to fabricate nanocomposite membranes with superior gas separation performance. Our Ti3C2-Pebax membranes achieved CO2/N₂ and CO₂/H₂ separation efficiencies that exceeded current state-of-the-art technologies, enabling cost-effective CO2 capture at $29/ton of separated CO2. Furthermore, Ti3C2-Matrimid 5218 membranes showed a more than twofold increase in both CO2 permeability and CO2/CH4 selectivity, which molecular dynamics simulations and characterization attributed to strong interfacial interactions between the polymer chains and Ti3C2. Lastly, Ti3C2-graphene oxide membranes showed H2/CO2 selectivity 364% and 77% higher than those of pristine Ti3C2 and graphene oxide membranes, respectively. These findings highlight the potential of pristine and surface-modified Ti3C2 MXene for enhancing the efficiency and performance of gas separation membranes and metal-ion adsorbents, particularly in cost-effective CO2 capture and environmentally critical applications like mercury ion removal.

Masoud Soroush is a Professor of Chemical and Biological Engineering and an Affiliate Professor of Materials Science and Engineering at Drexel University. He also directs the Future Layered nAnomaterials Knowledge and Engineering (FLAKE) Consortium, which comprises over 30 researchers from Drexel University, the University of Pennsylvania, and Purdue University. Dr. Soroush is an Elected Fellow of the American Institute of Chemical Engineers (AIChE) and a Senior Member of the Institute of Electrical and Electronics Engineers (IEEE). He earned his BS in Chemical Engineering from Abadan Institute of Technology in Iran, and both his MS and PhD in Chemical Engineering from the University of Michigan, Ann Arbor, where he also received an MS in Electrical Engineering. Poster Awards from the American Society for Precision Engineering (2017, 2018), and the Outstanding Teaching by an Assistant Professor Award from the Department of Mechanical Engineering at the University of Texas at Austin (2017).