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

This work aimed to develop green biodegradable film using red seaweed (Kappaphycus alvarezii) as a base matrix and calcium carbonate (CaCO3) as a filler to enhance the properties of the red seaweed material for plasticulture purpose. CaCO3 which was produced by microbially induced precipitation (MB-CaCO3) using Bacillus sphaericus, was characterized and compared with the commercial CaCO3 (C CaCO3). FESEM image revealed that the size of MB-CaCO3 was smaller and more uniform compared to C-CaCO3. FTIR and XRD analyses confirmed the existence of crystalline polymorph of calcite in MB-CaCO3, which contained a higher percentage of calcite than C-CaCO3. However, the crystallinity and thermal stability of MB-CaCO3 was lower than C-CaCO3. From the results of physical, mechanical and thermal properties of composite films filled with C-CaCO3 and MB-CaCO3 fillers, the optimum loading of C-CaCO3 and MB-CaCO3 was found at 0.1% and 0.15%, respectively. Composite films filled with MB-CaCO3 promote brighter film, better water barrier, hydrophobicity and biodegradability compared to C-CaCO3. Since the effect of MB-CaCO3 on film functional properties was comparable to C-CaCO3, it can be used as an alternative to C-CaCO3 as inorganic filler for composite films in agriculture applications. (C) 2018 Elsevier Ltd. All rights reserved.