Biomedical Engineering Reference
In-Depth Information
O
O
CH
2
CH--C--O--(-CH
2
CH
2
O-)
n
--C--CH CH
2
O
CH
2
H
2
C
O
O
n
O
FIGURE 11.6
Chemical structure of PEG-DA.
O
CH
2
O
CH
3
+ H
2
C
O
n
O
Methyl radical
from
photoinitiator
PEG diacrylate
O
O
CH
2
H
2
C
+
CH
2
+ H
2
C
O
O
O
O
n
n
O
O
O
O
H
2
C
O
CH
2
CH
+
O
O
O
n
n
O
O
PEG hydrogel
FIGURE 11.7
Photopolymerization reaction of PEG-DA molecules initiated by the methyl
radical from photoinitiator (DMPA) resulting in formation of the PEG hydrogel.
of PEG-DA molecules and initiates the cross-linking resulting in the formation of PEG hydrogel as
depicted in
Figure 11.7
[28]
. Silanization was performed to functionalize the surface of silicon sub-
strates with a chemical substance that can function as a coupling agent between the PEG hydrogel
and the silicon substrate. The treatment with “piranha” solution resulted in a hydrophilic surface due
