Synthesis and characterisation of chitin from periwinkle (Tympanotonus fusatus (L.)) and snail (Lissachatina fulica (Bowdich)) shells.

This study characterizes chitin extracted from bio-sources of snail and periwinkle using varied combinations of acid and alkali concentrations. A three level factorial design of experiment with alkali and acid concentrations was used. FTIR, XRD and SEM were used to investigate the structural changes after treatments. Results reveal that both alkali and acid concentrations significantly affect the development of the functional groups and their intensities in the extracted chitin. A certain combination of concentration of acid and alkali can be used to obtain chitin with high degree of order (Crystallinity Index (CrI) > 0.9) and a degree of de-acetylation (DD > 50%). This results in combined high crystallinity and degree of de-acetylation. The study also established that certain combination of acid and alkali concentrations could lead to alpha to beta transformation in chitin structure. [ABSTRACT FROM AUTHOR]