Presentation

Nanomaterials for Membrane-Based Water Treatment Applications

 

Dr. Mauter’s presentation explored the utilization of nanotechnology to help tackle environmental problems, specifically, issues of water quality. Below, Dr. Mauter explains why further technology, such as nanotechnology, is needed to address the environmental problem of water treatment.

 

Decline in water quantity and quality has accelerated the adoption of membrane-based water treatment technologies (reverse osmosis and ultrafiltration) as reliable sources of potable water. Widespread implementation of membrane-based water treatment technologies, however, is constrained by the energy requirements of conventional membrane processes. A suite of novel selective and/or reactive membranes will be needed to meet water resource needs in an energy-constrained environment.

 

Dr. Mauter’s presentation demonstrated how nanotechnology can be used to address this problem. Here Dr. Mauter explains how membranes can be manipulated on the nano scale to improve their function.

 

The present work exploits the unique properties of carbon nanotubes (CNTs) and Ag nanoparticles in two novel membrane architectures. Theory predicts high flux and high salt rejection through aligned CNT membranes, but current fabrication techniques cannot produce membranes that meet theoretical requirements for desalination through a size exclusion mechanism. This work demonstrates the feasibility of post-synthesis nanotube alignment to fabricate a membrane with SWNT diameters small enough to reject hydrated salt ions. In operational membrane systems, biofouling substantially increases both membrane resistance and the energy demands of water treatment.

 

Dr. Mauter’s method of aligning carbon nanotubes, so that they can be used for water treatment membranes is described in her own words below.

 

Here, we present a lyotropic liquid crystalline mesophase that supports the facile alignment and scalable synthesis of oriented nanocomposites.  Magnetically aligned liquid crystalline (LC) mesophases act as structure directing templates for the alignment of sequestered nanomaterials.  The slow relaxation of the viscous gel-like system preserves nanomaterial orientation until post-alignment photopolymerization of the mesophase forms the nanocomposite support matrix.  The space-pervasive nature of magnetic fields provides straightforward control over nanomaterial orientation and excellent compatibility with thin-film geometries. The availability of large homogeneous and high field magnets ensures that this approach scales easily to macroscopic dimensions.  The effectiveness of the supporting matrix is contingent upon the diamagnetic anisotropy of the cylindrical micelles, the accessibility of the order-disorder transition temperature, and the controlled polymerization of the matrix. 

 

Dr. Mauter’s presentation ended with an explanation of the importance of understanding the fate of nanoparticles within the environment, to both the environment and human health.