Do more pores in a sieve allow more liquid to flow through it?
As material scientists have uncovered, this seemingly simple question may have an unexpected answer at the nanoscale.
And it could have important implications in the development of water filtration, energy storage and hydrogen production.
Scientists have discovered the opposite can occur at the nanoscopic level.
The chemical environment of the sieve and the surface tension of the liquid play a surprisingly important role in permeability.
The researchers observed that a density of pores doesn't necessarily lead to higher water permeability.
The study shines new light on the mechanisms that govern water flow through GO membranes.
GO is an extremely thin form of carbon that has shown promise as a material for water purification.
The chemical compound is made up of a single layer of carbon atoms with oxygen and hydrogen atoms attached.
In chemistry, molecules can have what's known as "functional groups" that are either hydrophobic or hydrophilic.
The pores in graphene can also be hydrophobic or hydrophilic.
Despite the presence of many tiny holes in the GO filters, they exhibited a complete blockage of water in the case of hydrophobic pores.
surface tension also contributes to the water interaction with the GO pores.
Surface tension arises because molecules, like water, want to stick together.
When confined in a sufficiently small space, the bonds between water and surrounding solid surfaces can act to move the water.