Chemistry Reference
In-Depth Information
FIGURE 4.15
“Move-prove-connect” sequence with the neutral and azide-carrying den-
dronized polymer
PG3A
and the edge of the topmost graphite plane of HOPG precoated with a
monolayer of C
12
H
25
NH
2
. Reprinted from Ref. [49] with permission of Wiley-VCH.
distinguished from the circular DNA
puC19
by its larger thickness and its topology
since
and the DNA have been
moved toward each other (Figure 4.14b and c), and it is shown that pure contact does
not link the chains such that the junction would hold as one moves one chain apart
from the other (Figure 4.14d). After pushing the chains toward each other in tight
contact again (Figure 4.14e) and illuminating the sample for 5min with UV-light at
254 nm the induced junction was mechanically tested by pulling first on the
puC19
is a circular plasmid (Figure 4.14a). First
PG3A
PG3A
(Figure 4.14f and g) and then on the DNA (Figure 4.14h), showing that the junction
withstands the employed forces when being dragged across the surface and the chains
come straight off the junction. The DNA chain was furthermore over-stretched by a
factor of 1.3 during testing the junction to a global contor-length of L
¼
1136 nm
(L
0
¼
,
onC
12
H
25
NH
2
precoatedHOPG is welded to the edges of a topmost graphene plane of
HOPG. These rather different cases illustrate the considerable potential evolving from
the symbiosis of a powerful physical method, the AFM, with a powerful chemical
system, the dendronized polymers.
878 nm). Finally, Figure 4.15 shows a case in which the same polymer,
PG3A
4.6 SUMMARY AND OUTLOOK
The four examples illuminated in this chapter mirror the width of basic and applied
research presently going on in the field of dendronized polymers. Now that finally also
