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Shuai, et al.
3.2 Characterization C=O stretch of PLLA. Interestingly, the
C=O peak shifted to high wavenumber when
Raman spectroscopy was used to demonstrate GO was introduced into the PLLA scaffold,
the presence of GO in PLLA scaffolds and
their interactions. As shown in Figure 2A, the demonstrating the possibly interaction between
Raman spectrum obtained for PLLA showed PLLA and GO because of hydrogen bonding.
three obvious characteristic peaks at 871 Geng et al. also reported a similar conclusion [48] .
cm , 1451 cm , and 2942 cm . The PLLA/ Water contact angle measurement was used
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GO scaffold also showed three characteristic to detect the hydrophilic properties of PLLA
peaks in the same position. There were two new and PLLA/GO scaffolds with 0.3%, 0.6%, 0.9%,
characteristic peaks appearing in the PLLA/ and 1.2% GO. The water contact angle of PLLA
GO spectra, representing the D (1330 cm ) and was 88.98°, which indicated that it had poor
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G (1544 cm ) peaks of GO, which confirmed hydrophilic properties. The water contact angle
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the presence of GO in the PLLA matrix. To began to decrease when GO was introduced.
explore the interaction between PLLA and Water contact angle continuously decreased with
GO, the partial spectra in Figure 2A were increasing GO content, indicating that GO was
magnified and showed, as shown in Figure 2B. beneficial to improve the hydrophilic properties
The characteristic peaks at 1761 cm were of the PLLA scaffold. To further explore the
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A B

C D

Figure 2. (A) Raman spectra of PLLA and PLLA/GO, and (B) partial magnification in spectra a. (C) Water
contact angle of the PLLA scaffolds with 0%, 0.3%, 0.6%, 0.9%, and 1.2 wt % GO. (D) Water absorption
rate of the PLLA scaffolds with 0%, 0.3%, 0.6%, 0.9%, and 1.2 wt % GO after immersing in aqueous
solution for different time. GO was successfully introduced into the PLLA scaffold and interacted with
PLLA. Hydrophilicity and water absorption capacity increased with increasing GO.

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