I-Corps: Application Development for Graphene Oxide Nanofiltration Membranes

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The broader/commercial impact of this I-Corps project affects the significant energy consumption that is due to separation processes. From petroleum refinery to food and beverage production, many industrial processes need to overcome the entropy of mixing. Membrane separation is the most energy efficient method of separation, but commercial membranes are inherently limited by their material properties. In particular, high temperature, corrosive, or sterile processes are severely hindered by material selection. Currently, polymers are used for membranes with small molecular-weight cutoffs, while ceramics are applicable for larger contaminants. In many cases, heat is used to drive the separation because membranes are insufficient to provide required rejection. But, in the case of water desalination, membranes afford half to a quarter of the energy use per unit of water treated, illustrating the inherent inefficiencies of distillation or drying. This I-Corps project uses graphene oxide (GO) as a material platform with tunable chemistry to offer size-exclusion based membrane separation with increased robustness. In addition to permeability, temperature stability and resilience to cleaning chemicals offer operational cost savings. This project previously built a fundamentally new way of assembling membranes by using chemical cross linkers between GO sheets in order to leverage the low feedstock cost of GO, the improved permeability of a nanoporous thin-film membrane, and the increased resilience to organic foulants. Further, the production of these membranes was designed for manufacturing, incorporating only solution-based processes with analogues used in industry today. In the current work, with a deep understanding of the chemistry and physics of graphene oxide through the lens of separation mechanisms, it is anticipated that this system can open up many exciting opportunities for rGO membranes in a number of important separations.