University of Waterloo researchers have developed a novel method called droplet templating which will enable a new class of nanoparticle-based soft materials. The method allows for the creation of tiny droplets of one liquid inside of another without mixing the two.
The work, published in Materials Horizons, employs an aqueous based droplet onto which nanoparticles are assembled to form a strong outer shell which keeps each droplet intact and distinct. Once coated, these droplets can be filled with an array of nanoparticles before drying to form lightweight aerogel beads.
"This technique allows researchers to create hybrid aerogels by filling each droplet or bead with specific nanomaterials for different targeted uses," said Dr. Milad Kamkar, a professor in Waterloo's Department of Chemical Engineering. "Researchers can now control not only the composition but also where each droplet is arranged within a liquid, essentially making the droplets and the resulting soft materials and aerogels programmable."
The researchers believe the method could have profound impacts on wastewater treatment methods by loading the aerogel beads with different nanoparticles to target specific contaminates. Another process which could be improved with the method would be infusing the beads with metal-organic frameworks or other similar materials to capture carbon dioxide from the air.
"This technique allows researchers to create layered, gradient or mixed aerogels, opening up new possibilities for designing multifunctional materials," Kamkar added. "Scientists can now control the precise location of components and nanomaterials."