Papers Published

  1. Ahn, Sang-Jung and Lee, Woo-Kjung and Zauscher, Stefan, Fabrication of stimulus-responsive polymeric nanostructures by proximal probes, Materials Research Society Symposium - Proceedings, vol. 735 (2003), pp. 111 - 116 .
    (last updated on 2007/04/06)

    Abstract:
    The triggered control of interfacial properties on the nanometer scale holds significant promise for actuation in bio-nanotechnology applications where polymeric actuators may manipulate the transport, separation, and detection of biomolecules. To fabricate patterned, stimulus-responsive polymer brushes we have developed several methods that combine surface initiated polymerization (SIP) with dip-pen nanolithography (DPN). Surface-confined, stimulus-responsive polymer brush nanopatterns were fabricated by amplification of DPN patterned, self-assembled monolayers of 16-mercaptohexadecanoic acid on gold surfaces by SIP of N-isopropylacrylamide (NIPAAm). While free radical polymerization yielded only short polymer brushes (DP less than or equal 50), atom transfer free radical polymerization (ATRP) produced thick, uniform polymer brushes. For free radical polymerization the thickness of the polymer brush layer is a function of the lateral feature size and the initiator density and is maximal at pattern boundaries.

    Keywords:
    Polymers;Free radical polymerization;Nanotechnology;Surfaces;Self assembly;Gold;