Table 8.

FTIR spectral band of seaweed-based material.

Raw Material (Cited Reference)

Modified Material (Cited Reference)

κ-Carrageenan -D-galactose-4-sulphate 842–847 cm−1 [13,54,59,104,105] -3,6-anhydro-D-galactose 925 to 930 cm−1 [13,54,59,104,105] -C–O and C–C stretching of pyranose ring 1033- to 1038 cm−1 [54,59,106] -Sulphate ester 1219–1248 cm−1 [54,59,106] -Free OH, SO2 and NH groups stretching vibrations 3323 to 3331 cm−1 (broad) [54,59,106] ι-Carrageenan -Additional sulphate ester 805 cm−1 [105] -D-galactose-4-sulphate 845 cm−1 [105] -3,6-anhydro-D-galactose 930 cm−1 [105] λ-Carrageenan -High sulphate content 820–830 cm−1 (broad) [105] -D-galactose-4-sulphate 845 cm−1 [105] -3,6-anhydro-D-galactose 930 cm−1 [105]

κ-Carrageenan crosslinked with corn starch [53] -Shifted glycosidic linkages 1038 cm−1 to 1028 cm−1 -Shifted C–O bond stretching of corn starch 1150 cm−1 to 1152 cm−1 -Shifted sulphate ester 1219 cm−1 to 1236 cm−1 κ -Carrageenan blended with locust bean gum [33] -Shifted O–H stretching of hydroxyl groups because of an increase in hydrogen bond 3458 cm−1 to 3438 cm−1 κ-Carrageenan crosslinked with maltodextrin and plasticised with sorbitol [13] -Broadened sulphate ester band 1248 cm−1 κ-Carrageenan crosslinked with Arabic gum [54] -A new band of sulphate esters 400 cm−1 -A new band of glycosidic linkage 1034 cm−1