Temperature-enhanced solvent vapor annealing of a C3 symmetric hexa-peri-hexabenzocoronene: controlling the self-assembly from nano- to macroscale

Small. 2009 Jan;5(1):112-9. doi: 10.1002/smll.200801002.

Abstract

Temperature-enhanced solvent vapor annealing (TESVA) is used to self-assemble functionalized polycyclic aromatic hydrocarbon molecules into ordered macroscopic layers and crystals on solid surfaces. A novel C3 symmetric hexa-peri-hexabenzocoronene functionalized with alternating hydrophilic and hydrophobic side chains is used as a model system since its multivalent character can be expected to offer unique self-assembly properties and behavior in different solvents. TESVA promotes the molecule's long-range mobility, as proven by their diffusion on a Si/SiO(x) surface on a scale of hundreds of micrometers. This leads to self-assembly into large, ordered crystals featuring an edge-on columnar type of arrangement, which differs from the morphologies obtained using conventional solution-processing methods such as spin-coating or drop-casting. The temperature modulation in the TESVA makes it possible to achieve an additional control over the role of hydrodynamic forces in the self-assembly at surfaces, leading to a macroscopic self-healing within the adsorbed film notably improved as compared to conventional solvent vapor annealing. This surface re-organization can be monitored in real time by optical and atomic force microscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Microscopy, Atomic Force
  • Nanostructures / chemistry*
  • Polycyclic Compounds / chemistry*
  • Silicon / chemistry
  • Solvents / chemistry*
  • Surface Properties
  • Temperature*
  • Thermodynamics

Substances

  • Polycyclic Compounds
  • Solvents
  • hexa-peri-hexabenzocoronene
  • Silicon