Source: Xconomy, Dec 10
Membrion, a Seattle-based cleantech startup, recently raised $2.2 million in new funding to give the company a boost along the path to commercialization. It engineers flexible membranes using silica gel, the same material in the small bags manufacturers place inside new shoes and bags of jerky and edible seaweed. These bags contain tiny moisture-absorbing beads that can help the products they’re packaged with stay dry.
One potential application is water purification; filtering ions from a wastewater stream is done most effectively by using membranes with small pores—from 0.5 nanometers to 1.5 nanometers, Plaza says. The small-pore design is similar to that of the desiccants included in consumer product packaging, Membrion says.
Other planned applications for the company’s membranes include fuel cells and large batteries for grid-scale energy storage. These “flow” batteries, like the one installed at a utility north of Seattle in early 2017, offer the promise of letting consumers use more renewable energy and reducing dependence on fossil fuels.
The company’s process for making its “ceramic” membranes involves taking a piece of nonwoven glass fiber—similar to the material many boats are made of—covering it with silica gel, and curing it in an acidic bath, Plaza says. “That basically acts in the same way heat does with a traditional ceramic, shrinks the silica into a hard ceramic surface, and allows us to control … the pore size,” he says.