to selective solvents for either of the blocks, the surface tension or contact angle of the
coated substrate could be reversibly switched. Such adaptive surfaces may have
potential applications for anti-fouling and self-cleaning surfaces.
Finally, fluorescent dye molecules as well as QDs were successfully
immobilized in the hydrophobic part of the double layer of block copolymer
vesicles below 100 nm in size. In the case of the QDs, the double layer was
observed to strongly curve around the guest particles without becoming
destabilized. The limit of stable confinement in terms of size and polarity of the
guest molecules will be subject of future investigations. The presented example
demonstrates that 2D confinement within a vesicle shell principally allows control
of the spatial arrangement of nanoparticles in solution.
6 Towards Synthesis on an Insulating Surface
6.1 Introduction
Synthesizing macromolecules or studying the structure and dynamics of
macromolecules in confining geometries is a challenging element of polymer
science. A surface can also serve as confining geometry for both polymer synthesis
and polymer characterization. Immobilizing polymerizable monomers on solid
surfaces with suitable anchor groups and subjecting them to network formation is
a well-established coating technique. A much more sophisticated approach to
surface-bound polymer synthesis is the deposition of reactive monomers on
conductive or insulating substrates and the promotion of light- or heat-driven
polymerizations under in-situ control by scanning probe techniques. As well as
the possibility of following macromolecule formation with atomic precision in real
space, the surface can now also act as template by either stabilizing reactive
intermediates or by pre-organizing them into a desired pattern.
In general, creating complex polymer architectures on surfaces offers a great
potential for future applications, e.g., in the fields of (bio)sensors and molecular
electronics. The bottom-up construction of functional devices from molecular
building blocks provides utmost control in tailoring the properties and functionality
of materials. Encoding the resulting structure and functionality in the molecular
building blocks has been explored extensively in the field of molecular self-assembly
[281]. However, because molecular self-assembly relies on weak, reversible intermolecular interactions to arrive at the (local) thermodynamic minimum, the resulting
structures are inherently unstable and might not survive further processing or harsh
operation conditions. Moreover, when aiming at electrically conductive structures,
conjugated structures are desired because of their superior electron transport
properties. To provide stability and electric conductivity, on-surface synthesis has
recently been explored as a promising route to the creation of covalently linked
molecular structures [282, 283]. So far, these studies have been limited to metallic
194
K. Binder et al.
coated substrate could be reversibly switched. Such adaptive surfaces may have
potential applications for anti-fouling and self-cleaning surfaces.
Finally, fluorescent dye molecules as well as QDs were successfully
immobilized in the hydrophobic part of the double layer of block copolymer
vesicles below 100 nm in size. In the case of the QDs, the double layer was
observed to strongly curve around the guest particles without becoming
destabilized. The limit of stable confinement in terms of size and polarity of the
guest molecules will be subject of future investigations. The presented example
demonstrates that 2D confinement within a vesicle shell principally allows control
of the spatial arrangement of nanoparticles in solution.
6 Towards Synthesis on an Insulating Surface
6.1 Introduction
Synthesizing macromolecules or studying the structure and dynamics of
macromolecules in confining geometries is a challenging element of polymer
science. A surface can also serve as confining geometry for both polymer synthesis
and polymer characterization. Immobilizing polymerizable monomers on solid
surfaces with suitable anchor groups and subjecting them to network formation is
a well-established coating technique. A much more sophisticated approach to
surface-bound polymer synthesis is the deposition of reactive monomers on
conductive or insulating substrates and the promotion of light- or heat-driven
polymerizations under in-situ control by scanning probe techniques. As well as
the possibility of following macromolecule formation with atomic precision in real
space, the surface can now also act as template by either stabilizing reactive
intermediates or by pre-organizing them into a desired pattern.
In general, creating complex polymer architectures on surfaces offers a great
potential for future applications, e.g., in the fields of (bio)sensors and molecular
electronics. The bottom-up construction of functional devices from molecular
building blocks provides utmost control in tailoring the properties and functionality
of materials. Encoding the resulting structure and functionality in the molecular
building blocks has been explored extensively in the field of molecular self-assembly
[281]. However, because molecular self-assembly relies on weak, reversible intermolecular interactions to arrive at the (local) thermodynamic minimum, the resulting
structures are inherently unstable and might not survive further processing or harsh
operation conditions. Moreover, when aiming at electrically conductive structures,
conjugated structures are desired because of their superior electron transport
properties. To provide stability and electric conductivity, on-surface synthesis has
recently been explored as a promising route to the creation of covalently linked
molecular structures [282, 283]. So far, these studies have been limited to metallic
194
K. Binder et al.