- Kaholek, M. and Woo-Kyung Lee and LaMattina, B. and Caster, K.C. and Zauscher, S., Fabrication of stimulus-responsive nanopatterned polymer brushes by scanning-probe lithography,
Nano Lett. (USA), vol. 4 no. 2
pp. 373 - 6 [nl035054w] .
(last updated on 2007/04/06)
Stimulus-responsive, surface confined poly(N-isopropylacrylamide) (pNIPAAM) brush nanopatterns were prepared on gold-coated silicon substrates in a "grafting-front" approach that combines "nanoshaving", a scanning probe lithography method, with surface-initiated polymerization using atom transfer radical polymerization (ATRP). The reversible, stimulus-responsive conformational height change of these nanopatterned polymer brushes was demonstrated by inverse transition cycling in water, and water-methanol mixtures (1:1, v:v). Our findings are consistent with the behavior of laterally confined and covalently attached polymer chains, where chain mobility is restricted largely to the out-of-plane direction. Our nanofabrication approach is generic and can likely be extended to a wide range of vinyl monomers