Figure 2 TEM photos of MTCFs@SIP@CBMA under different
WBSA-SIPMTFs/WCBMA (a); effect of
WBSA-SIPMTFs/WCBMA on the adsorption
capacity and imprinting factor of MTCFs@SIP@CBMA (b)
Characterization of MTCFs@SIP@CBMA
Morphologies observation
SEM and TEM images of each product and EDS analysis results of
MTCFs@SIP@CBMA are given in Figure 3. As can be seen from Figure 3A and
E, MTFs presented a hollow fibrous structure with an average diameter of
105 nm. In addition, the cavities contained black nanoscale particles.
Through analysis, it was believed that these nanoparticles with high
mass thick contrast were the conversion products of
FeCl3 during the carbonization of polymer nanofibers
(TPNFs). Magnet and VSM tests displayed that MTCFs exhibited magnetic
responsiveness, so it was inferred that these nanoparticles may be
Fe3O4 or iron element. After the coating
of imprinted layer, the surface of BSA-MTCFs@SIP became significantly
rough compared with the smooth surface of MTCFs, and the fiber diameter
increased slightly (Figure. 3b and f). The average diameter of
BSA-MTCFs@SIP was121 nm, which was an increase of 16 nm compared to
MTCFs. The calculated thickness of imprinting layer was 8 nm. This
thickness was sufficient to achieve an effective imprinting of BSA with
a size of 14 nm×4 nm×4 nm. SEM and TEM photos of MTCFs@SIP@CBMA are
presented in Figure 3c and g. By measurement, the average diameter of
MTCFs@SIP@CBMA fibers increased by 4 nm compared with that of
BSA-MTCFs@SIP, indicating the successful graft of CBMA polymer chain.
The thickness of CBMA layer was 2 nm. Compared Figures 3c with d, it was
observed that the surface morphology of MTCFs@NIP@CBMA was not
significantly different from that of MTCFs@SIP@CBMA. In the dark field
image of MTCFs@SIP@CBMA (Figure 3h), it displayed a different degree of
brightness and darkness on the tube wall, illustrating the coating of
the PDA imprinted layer and the grafting of the CBMA polymer chain. The
extremely bright nanoscale dots in the tube were inorganic magnetic
nanoparticles. The EDS analysis results of MTCFs@SIP@CBMA are shown in
Figure 3i-1. It can be seen that MTCFs@SIP@CBMA contained abundant C, N,
O and Fe elements. The presence of N and O indicated that the surface of
MTCFs was coated with PDA imprinted layer and CBMA polymer layer. Fe
element was derived from magnetic nanoparticles.