Iain Hosie discusses van der Waals forces and their importance to nanofibres.
Van der Waals forces: attraction forces between neighbouring molecules.
Van der Waals forces are very important in the nanofibre industry because, of the dimensions of the fibres that we’re creating, one of the properties that come out of these small fibres is their molecular attraction.
A nanofibre is a very fine fibre. A human hair typically is about 50 000 nanometres in width. We’re creating fibres here which are about 100 nanometres, so we’re talking 500 times thinner than a human hair.
If you can get fibres and any particles down to the nanoscale, they can take on all sorts of different properties. For example, with van der Waals forces, a thick fibre like the human hair will not display any attractive force, but if we can take the same materials and get them to 100 nanometres in scale, they’ll start to attract dust.
So in air filtration, if a dust particle is whizzing beside one of our fibres, they tend to be attracted to it. And it’s a property that will never run out, it’s not something that will dissipate over time – this is a molecular attraction – so it is something that will stay with the fibre forever.
Albert McGhee, Hansol Cha
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