Spin coating is a standard method for preparing thin films of soluble polymers. In this research the technique is used to prepare a 130Å thick film of poly(methyl methacrylate) (PMMA) on a polystyrene substrate.
At this scale the film is unstable, and, if gently heated, it reduces its surface energy by a process known as 'spinodal dewetting'. This results in a pattern of PMMA droplets of uniform size and regular distribution (a 'regular length scale'). Pre-casting the PMMA film on a mechanically treated glass substrate can orient the pattern of drops.
Spin coating and patterned polymer surfaces
The ability to manipulate polymer structures at the nano-scale (as in this case) opens up exciting possibilities in nano-technology.
References
A.M. Higgins and R.A.L. Jones Anisotropic spinodal dewetting as a route to self-assembly of patterned surfaces. Nature 404 (2000) 476.
This feature is based on work carried out by Prof Richard Jones:
© The University of Sheffield Polymer Centre, 2008.
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