Nanopatterning in Langmuir-Blodgett monolayers of a thermoresponsive double hydrophilic block copolymer studied by atomic force microscopy

J Nanosci Nanotechnol. 2011 Apr;11(4):3151-61. doi: 10.1166/jnn.2011.3726.

Abstract

The microphase-separation of Langmuir-Blodgett (LB) monolayers of a rhodamine B (RhB) end-labeled double hydrophilic block copolymer (DHBC), RhB-Poly(N,N-dimethylacrylamide)-b-poly(N,N-diethylacryl-amide) (RhB-PDMA(207)b-PDEA177) and the 1:1 segmental mixture of PDEA and RhB-PDMA homopolymers was followed by AFM. The DHBC LB films revealed a loose distribution of nano-aggregates with variable geometries below the lower critical solution temperature (LCST) of PDEA (32 degrees C) and low surface pressure (3 mN m(-1)). By increasing either the temperature above the LCST of PDEA or the surface pressure beyond the immersion regime of PDMA in the subphase (7 mN m(-1)) a dense nanopatterning was obtained. The absence of a corresponding regular nanopatterning in LB films of mixed homopolymers with the same composition highlights the role of the covalent bonding between PDEA and PDMA on the self-segregation of the two blocks at the air-water interface.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Materials Testing
  • Membranes, Artificial*
  • Microscopy, Atomic Force / methods*
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Particle Size
  • Polymethacrylic Acids / chemistry*
  • Surface Properties
  • Temperature

Substances

  • Membranes, Artificial
  • Polymethacrylic Acids
  • poly(2-(dimethylamino)ethyl methacrylate)-block-poly(2-(diethylamino)ethyl methacrylate)