Ariel Atkinson1 Yuqiang Bi1 Peter Firth1 Omar Alrehaili1 Paul Westerhoff1 Zachary Holman1

1, Arizona State University, Tempe, Arizona, United States

Impregnating water treatment membranes with nanomaterials can reduce fouling, increase water permeability, and add extra functions; all of which potentially lead to increased energy efficiency in the membrane treatment process. We developed a new spray coating method to modify the surface of water treatment membranes with nanomaterials. We evaluated this method by coating PVDF ultrafiltration (UF) membranes, using varying deposition parameters, with gold and silver nanoparticles having various surface functionalizations. We will discuss our results in terms of (1) deposition efficiency, (2) characteristics of the nanoparticle coatings (e.g. uniformity, nanoparticle integrity, repeatability of coating), (3) nanoparticle loading as a function of coating method (e.g. nanoparticle choice, deposition time), (4) membrane performance (i.e. water permeability), and (5) nanoparticle stability on membrane surfaces. We will identify ideas to improve the spray coating method for various membrane applications, and areas that need to be further investigated. The nanoparticle spraycoating method has advantages over some other nanoparticle impregnation methods, including applicability to multiple membrane substrates, ability to directly coat the surface where the nanoparticles are most effective, the ability to coat with varying nanomaterials or cocktails of nanomaterials, and no additional chemicals are required aside from the nanoparticles themselves. Furthermore, this method can easily be scaled-up and integrated into current membrane manufacturing to coat membranes at a rate of m2 per minute. Overall, the spray coating method is a flexible and reliable method for nano-enabling water treatment membranes and can potentially improve energy efficiency of the membrane treatment process.