Tuning the Dimensions and Periodicities of Nanostructures Starting from the Same Polystyrene-block-poly(2-vinylpyridine) Diblock Copolymer
The controlled tuning of the characteristic dimensions of two-dimensional arrays of block-copolymer reverse micelles deposited on silicon surfaces is demonstrated. The polymer used is polystyrene-block-poly(2-vinylpyridine) (91500-b-105000 g mol–1). Reverse micelles of this polymer with different aggregation numbers have been obtained from different solvents. The periodicity of the micellar array can be systematically varied by changing copolymer concentration, spin-coating speeds, and by using solvent mixtures. The profound influence of humidity on the micellar film structure and the tuning of the film topography through control of humidity are presented. Light scattering, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were used for characterization. As possible applications, replication of micellar array topography with polydimethylsiloxane and post-loading of the micelles to form iron oxide nanoparticle arrays are presented.