2.4.1 Chemical structure of carrageenan-based bioink
The Fourier-transform infrared spectroscopy (FT-IR) spectrum of the kc,
kc-s, and kc-c was analysed using Fourier-transformed
infrared-attenuated total reflectance (Nicolet Avatar 370, USA).
Moreover, the printing and non-printing FTIR spectra of kc-s and kc-c
were analysed. A background spectrum was collected before acquiring the
transmission infrared spectra of the samples. All the spectra were
between 4000 and 400 cm−1.