Supra-Amphiphiles for Controlled Self-Assembly and Disassembly - Molecular Self-Assembly: Advances and Applications - page 219

light irradiation (Fig. 6.10). This great change in wettability can be
cycled several times by alternating between UV- and visible-light
irradiation. The density of the responsive moieties on the surface is
also very crucial. If the density is too high, the movements of the

α

-CD
will be blocked. In addition, a low density cannot cause significant
changes of wetting ability. Our study indicates that a ratio of 1:6
between supra-amphiphiles and noncapped azobenzenes favors the
tuning of the wettability of the surface.

Figure 6.10 Responsive surfaces on the basis of rotaxane on surface.

Reproduced with permission of Ref. [37]. Copyright 2008,
Royal Society of Chemistry.

6.5 Outlook

The supra-amphiphile represents a new development of traditional
colloid science, and in the meantime it functions as a new building
block of self-assembly and disassembly for supramolecular
nanostructures. Supra-amphiphiles with different architectures
can be fabricated, which are driven by various noncovalent bonds.
Functional groups may be introduced readily without much
chemical synthesis. The relationship among molecular architecture,
supramolecular nanostructures, and the functions of the soft
materials should be studied further, thereby establishing the realm
of supramolecular engineering for well-defined nanostructured soft
materials.