Ma, X., Xie, Z., Liu, Z., Liu, X., Cao, T. and Zheng, Z. (2013), Adv. Funct. Mater.. doi: 10.1002/adfm.201203181
Polymer brushes of PMMA grown from a silicon surface using surface initiated ATRP are explored here as "electrets" to store electrostatic charges. The polymer brushes are "charged" using an AFM tip electrode or a gold coated PDMS stamp electrode. These charged patterns that are created by this technique are able to imobilize charged gold nanoparticles and are stable even in good solvents. The charge stability is examined in various solvents and in various temperatures. They cite that the charges deteriorate mostly by adsorption of counter ions over time, especially because the humidity was 60% while they were working.