Programmable droplets create next-generation materials
A research group led by Chemical Engineering Professor Milad Kamkar has developed a method to make it possible to have stable liquid droplets filled with different nanomaterials in another liquid.
This breakthrough research has created completely new categories of “programmable" droplet-based soft materials containing a range of nanomaterials. These droplets can be dried and turned into aerogel beads (highly porous materials) that can be deployed in many applications, such as carbon capture and wastewater treatment.
In complex environments, like wastewater streams with multiple contaminants, the aerogel beads can be layered or mixed to target specific pollutants.
“Each bead can absorb a specific type of pollution,” says Kamkar. “Making the material not just multifunctional, but strategically programmable.”
Professor Milad Kamkar
Carbon capture is another potential application. The aerogel beads could be filled with metal organic frameworks and other functional materials to capture the carbon dioxide because the beads are highly porous, providing a large surface area and active sites for interactions with carbon dioxide molecules.
These soft materials have been developed via a novel technique called “droplet templating”. This method leverages nanoparticle jamming at the interface between droplets and a continuous liquid phase. The jammed nanoparticles self-assemble into a robust interfacial layer around the droplet that stabilizes its shape.
Droplet templating is a one-step method that does not use chemicals, it is a cost-effective and easier way to make aerogels.
"This technique addresses a major challenge in shaping nanomaterials into macroscopic aerogel structures. It enables researchers to create hybrid aerogels by filling each droplet—and consequently each aerogel bead—with specific nanomaterials. Furthermore, by controlling the spatial localization of the droplets during assembly, it becomes possible to fabricate layered, gradient, or mixed soft materials and aerogels, opening new avenues for designing multifunctional and structurally complex materials.” says Kamkar, director of the Multi-scale Materials Design Center.
Kamkar and his team at Waterloo collaborated with researchers at the University of British Columbia and Drexel University.
A paper on their work, Droplet-templating soft materials into structured bead-based aerogels with compartmentalized or welded configurations, appeared in Material Horizons. Kamkar was recognized as an Emerging Investigator for this work and his contributions to the field of soft matter engineering.