Nano-Structuring by Molecular Self-Assembly

Abstract

the new physical, chemical, or biological properties of surfaces structured using these methods. There is a special emphasis on structuring mechanisms relying on selfassembly, self-organization, and non-equilibrium processes, i.e. parallel approaches to the fabrication of large-area structures with high short-range order and some long-range order. In addition to this purely bottom-up approach based on self-organization of molecules, we also combine these selforganization methods with top-down, soft lithography techniques such as microfluidics for larger scale patterning of surfaces.Here we describe some different approaches to structuring surfaces. The first approach uses the ability of a spin-coated solution of two different homopolymers to demix and form micro-to nano-structured thin films with different morphologies. A very similar approach, used to create even smaller structures, with a higher degree of order is based on the phase separation of block-copolymers. This method gives chemically distinct domains with sizes ranging from 10 nm to 100 nm. Combining homopolymer and copolymer phase separation even allows the creation of polymeric films with structures on two length scales. The final example described here demonstrates the self-assembly and complexation properties of dendrimers, highly branched monodisperse macromolecules with welldefined structure, geometry, and monodispersity.Abstract: In contrast to conventional lithography techniques which will soon hit their limits in terms of feature size and fabrication cost, recent years have seen considerable progress in the development of selfassembling nano-structured surfaces. In the work reported here, surface structures on the submicron scale have been created from polymer, copolymer, nanoparticle, and dendrimer building blocks by employing phenomena such as self-assembly, self-organization and non-equilibrium processes. This low-cost approach is expected to result in a new generation of surfaces with novel physical and chemical properties.

Materials for Multiphoton 3D Microfabrication

“…Progress also has been made in using molecular, nanotube, and nanoparticle self-assembly to build structures with unique properties in a bottomup approach. [5][6][7] Such self-assembly processes, however, are limited predominantly to the formation of periodic structures. Fabrication of 3D objects of arbitrary shapes with feature sizes approaching those achievable by either photon or electron-beam lithography traditionally has been an extremely difficult task.…”

Cation‐Induced Unidirectional Self‐Assembly of Amino‐Terminated Poly(propylene imine) Dendrimers

“…Previously, it has been demonstrated that maltose‐functionalized PPI dendrimers can be used to template metal and semiconductor nanoparticles in aqueous media 3, 14. However, so far the self‐assembly of dendrimers has been studied predominantly on surfaces and in thin films 15–17. For example, De Schryver et al6, 18–20 demonstrated in a series of reports that long fibers of shape‐persistent polyphenylene dendrimers can be generated via spin‐coating and drop‐casting of solutions onto solid substrates.…”