US research team discovers new way to stabilise foams for lightweight materials
A research team at the Georgia Institute of Technology has created a new type of foam, called capillary foam, which helps create lightweight and sustainable materials.
The team includes Yi Zhang, who is co-advised by the Georgia Tech School of Chemical & Biomolecular Engineering study co-author and professor Sven Behrens, and professor Carson Meredith.
A combination of particles and a small amount of oil in water-based foams offer better foam stability, the researchers said.
The synergy of oil and particulate is counterintuitive as oils are usually used as defoaming agents; however, particles in the capillary foam form a stabilised network with the help of oil bridges.
Behrens said: "It's very difficult to stabilise foams, and we want foams that are stable for months or years.
"We've developed a way to make foams that is much easier and more broadly applicable than what is traditionally used."
The capillary foam is said to tackle problems associated with traditional foams, which form from a group of bubbles squeezed together. Foam is made of air and water, with sufactants traditionally added to stabilise it.
Liquid foams play a key role in various products and processes, including pharmaceutical formulation, oil production, food processing and cleaning products.
Lightweight dry-foams are made using the new process and could be used in the construction of buildings, automobiles and aeroplanes.
Image: Yi Zhang holding a porous solid material prepared from capillary foam. Photo: courtesy of Gary Meek.