Figure 1 shows the infrared spectrum for both crosslinked and non-crosslinked films. Both carrageenan and vanillin contain similar functional groups such as CH4, C=O, C-O-C, C-OH. There is no significant difference in the spectrum that can be detected for crosslinked and non-crosslinked film samples. The spectrum can be divided into upper and lower spectrum. In the upper spectrum for the region of 2000 – 3600 cm-1, O-H stretching (3100 – 3600 cm-1) and C-H stretching (2850 – 2930 cm-1) could be observed. Meanwhile, carrageenan has a few stretching that mark its functional groups in the lower region of spectrum (below 1000 cm-1). In the lower region, the spectrum shows the presence of C-O-S (galactose) stretching …show more content…
Meanwhile, the crosslinked film shows no smooth surface with some agglomeration or entanglement. The entanglement is a portion of interactions such as crosslink process that been entrapped and act as the physical junction in the network (Queslel and Mark, 1984). The differences of SEM result may further suggest that vanillin has been physically crosslinked with carrageenan and does not embedded in the carrageenan matrix or network. The non-smooth surface of the crosslinked film may indicate that the crosslinked material may easily disintegrate compared to the smoother surface of the non-crosslinked film. The smooth surface of non-crosslink may due to better bonding between the particles (Picker; 1999) which may enhance the swelling capability. Furthermore, the clear complexes of helixes or entanglement may indicate the defect of the network and produced the exothermic peak in DSC result. A study on fabrication of nano fiber from alginate (Nie et al. (2008) found that the entanglement may increase the flexibility of chains of alginates. This flexibility may promote the swelling capability of the non-crosslink