Microbial-induced CaCO3 filled seaweed-based film for green plasticulture application

Abstract This work aimed to develop green biodegradable film using red seaweed ( Kappaphycus alvarezii ) as a base matrix and calcium carbonate (CaCO 3 ) as a filler to enhance the properties of the red seaweed material for plasticulture purpose. CaCO 3 which was produced by microbially induced precipitation (MB-CaCO 3 ) using Bacillus sphaericus , was characterized and compared with the commercial CaCO 3 (C CaCO 3 ). FESEM image revealed that the size of MB-CaCO 3 was smaller and more uniform compared to C CaCO 3 . FTIR and XRD analyses confirmed the existence of crystalline polymorph of calcite in MB-CaCO 3 , which contained a higher percentage of calcite than C CaCO 3 . However, the crystallinity and thermal stability of MB-CaCO 3 was lower than C CaCO 3 . From the results of physical, mechanical and thermal properties of composite films filled with C CaCO 3 and MB-CaCO 3 fillers, the optimum loading of C CaCO 3 and MB-CaCO 3 was found at 0.1% and 0.15%, respectively. Composite films filled with MB-CaCO 3 promote brighter film, better water barrier, hydrophobicity and biodegradability compared to C CaCO 3 . Since the effect of MB-CaCO 3 on film functional properties was comparable to C CaCO 3 , it can be used as an alternative to C CaCO 3 as inorganic filler for composite films in agriculture applications.