Biodegradable Seaweed-Based Composite Films Incorporated With Calcium Carbonate Generated By Bacillus Sphaericus

Seaweed-based films have been trending in the recent years due to its nutritional benefits, abundance, compatibility and biodegradability. However, the hydrophilic nature of seaweed film has been limiting its water barrier, mechanical and thermal performances. Therefore, this study is purposed to develop biodegradable film using raw red seaweed (Kappaphycus alvarezii) as a matrix and incorporated with microbially induced calcium carbonate precipitates (M-CaCO3) to further enhance the film performances. In order to determine the enhancement of film properties, seaweed-based composite films incorporated with different filler loading [0.06, 0.08, 0.10, 0.15, 0.20 and 0.50 (wt. %)] of M-CaCO3 were characterized based on physical, mechanical, thermal, biodegradability, morphological and crystallinity using various characterization techniques such as FESEM, EDX, FT-IR XRD and TGA. The properties of the films were then compared with the films incorporated with the commercial calcium carbonate (C-CaCO3). The optimum loading was attained by 0.15 wt. % M-CaCO3 and 0.10 wt.% C-CaCO3 based on the results of physical, mechanical and thermal properties. It has proven that moisture absorption and water vapour permeability was significantly (p<0.05) reduced while the contact angle, tensile strength, tensile modulus, elongation at break and thermal stability were significantly enhanced upon increasing filler loading from 0.06 wt. % up to 0.15 wt. % M-CaCO3 and 0.10 wt.% C-CaCO3 loadings, respectively

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 (CCaCO3). FESEM image revealed that the size of MB-CaCO3 was smaller and more uniform compared to CCaCO3. FTIR and XRD analyses confirmed the existence of crystalline polymorph of calcite in MB-CaCO3, which contained a higher percentage of calcite than CCaCO3. However, the crystallinity and thermal stability of MB-CaCO3 was lower than CCaCO3. From the results of physical, mechanical and thermal properties of composite films filled with CCaCO3 and MB-CaCO3 fillers, the optimum loading of CCaCO3 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 CCaCO3. Since the effect of MB-CaCO3 on film functional properties was comparable to CCaCO3, it can be used as an alternative to CCaCO3 as inorganic filler for composite films in agriculture applications

Enhancement in the physico-mechanical functions of seaweed biopolymer film via embedding fillers for plasticulture application—a comparison with conventional biodegradable mulch film

This study aimed to compare the performance of fabricated microbially induced precipitated calcium carbonate– (MB–CaCO3) based red seaweed (Kappaphycus alvarezii) bio-polymer film and commercial calcium carbonate– (C–CaCO3) based red seaweed bio-film with the conventional biodegradable mulch film. To the best of our knowledge, there has been limited research on the application of commercial CaCO3 (C–CaCO3) and microbially induced CaCO3 (MB–CaCO3) as fillers for the preparation of films from seaweed bio-polymer and comparison with biodegradable commercial plasticulture packaging. The results revealed that the mechanical, contact angle, and biodegradability properties of the polymer composite films incorporated with C–CaCO3 and MB–CaCO3 fillers were comparable or even superior than the conventional biodegradable mulch film. The seaweed polymer film incorporated with MB–CaCO3 showed the highest contact angle of 100.94°, whereas conventional biodegradable mulch film showed a contact angle of 90.25°. The enhanced contact angle of MB–CaCO3 resulted in high barrier properties, which is highly desired in the current scenario for plasticulture packaging application. The water vapor permeability of MB–CaCO3 based seaweed films was low (2.05 ± 1.06 g·m/m2·s·Pa) when compared to conventional mulch film (2.68 ± 0.35 g·m/m2·s·Pa), which makes the fabricated film an ideal candidate for plasticulture application. The highest tensile strength (TS) was achieved by seaweed-based film filled with commercial CaCO3 (84.92% higher than conventional mulch film). SEM images of the fractured surfaces of the fabricated films revealed the strong interaction between seaweed and fillers. Furthermore, composite films incorporated with MB–CaCO3 promote brighter film, better water barrier, hydrophobicity, and biodegradability compared to C–CaCO3 based seaweed polymer film and conventional mulch film. From this demonstrated work, it can be concluded that the fabricated MB–CaCO3 based seaweed biopolymer film will be a promising candidate for plasticulture and agricultural application