3. Results and discussion
3.1. PEG bis(amine) grafting PMMA/SPIONs characterization
The PMMA/SPIONs hybrid nanoparticles with the grafting
agents on the surface of the particles were confirmed by FT-IR, as
shown in Fig. 1A. The FT-IR spectrum of the uncoated SPION shows
no significant peak, while a prominent peak for the PMMA-coated
SPION appears at 1717 cm1
, due to the vibrational stretching
from the ester carbonyl group. The two bands at 2942 cm1 and
2830 cm1 can be assigned to the C–H bond vibrations stretching
from –CH3 and –CH2- groups, respectively. In the FTIR spectra
(Fig. 1A) of the SPIONs/PMMA-COOH, the broad band near
3400 cm1 is the O–H bond in the carboxyl group, and the C¼O
stretching is around at 1637–1700 cm1 [21–25]. PEG bis(amine)-
grafted on PMMA-SPIONs containing –NH2 group and N–H bond
from the amine yield peaks at 3069 cm1 and 3276 cm1
, respectively.
Meanwhile, to the right of the amine peaks, the bending
peaks of C¼O and the NH absorption peak are clearly observed
at 1621 cm1
and at1527 cm1
, respectively. These lead to a conclusion
that the PEG bis(amine) is successfully grafted on SPIONs/
PMMA. From above discussions, the prepared polymer is con-
firmed as macromolecular PMMA [26,27].
In rece