Advanced Photothermal Nanomaterials for Desalination Applications

G. Zhang, S. Davis, N. Kevlich, Z. Zhou
Luna Innovations Inc.,
United States

Keywords: plasmonic, nanomaterials, photothermal, solar, desalination

Summary:

Novel nanomaterials (NPs) and advanced nanotechnologies greatly promote our current science technology and life. Nanomaterials with well-defined size, shape, composition, and surface functionalities offer multifunctional platforms for various applications. In the optical property, the interaction between light and nanomaterials can be dramatically enhanced at their resonances, such as the localized surface Plasmon resonance phenomenon. Luna Innovations Inc. is developing a number of advanced nanomaterials for optical applications. One of our current study focuses on a novel transition metal based plasmonic nanomaterial and it has clear advantages over the conventional photothermal material, including the low fabrication cost, better hardness, high melting point and excellent optical/chemical stability. In our work, the surface and optical properties of these plasmonic nanoparticles are investigated. Surface modification approaches are developed to fine tune the optical absorption/scattering behavior and improve the compatibility with polymer materials. These nanomaterials are successfully integrated into the membrane distillation (MD) techniques for the desalination of sea water based on the solar technique. MD is thermal driven process allowing the water vapor pass through the hydrophobic membrane’s pores from hot water feed side to permeate side due to the vapor pressure gradient. The composite coatings consisting of these plasmonic nanoparticles and polymer materials are fabricated on the conventional MD membrane surface by electrospinning process. The MD desalination process is driven by sunlight radiation and this can greatly decrease the electricity and fuel energy consumption. The results show that the novel plasmonic nanomaterial is a very promising material for the photothermal conversion due to its unique optical property and high stability. The solar supported MD desalination process has great potentials for the application in the water purification industry.