RIDING THE WAVE OF ECO-FASHION: SEAWEED PLASTIC REPLACING OUTDATED PLASTIC BAGS

On a global scale, a single person uses 83 plastic bags annually, an estimated 500 billion bags worldwide. Leading to it, plastic wraps are produced in over 141 million tonnes a year and are used as packaging material worldwide. The history of the slick and transparent plastic that we call plastic wraps was a mistake made by the chemist Ralph Wiley in the 1930s. Looking back at 70 years when plastic was not discovered gives the influence of it in modern days. Generally, plastic wraps are thin plastic films drawn out of PVC(Polyvinyl Chloride), commonly used in sealing and securing food items in containers. But the original plastic wrap was made from PVdC (Polyvinylidene Chloride). Over the last few years, many alternatives to PVC have been popular like LDPE (Low-Density Polyethylene), Linear low-density polyethylene (LLDPE), HDPE (High-Density Polyethylene), and, PET (Polyethylene terephthalate).

Even though, these are poor conductors, non-corrosive, cheap, strong, durable, and elastic, as the adage goes ”Every good comes with trouble”, plastics are one of the major pollutants that have devastating effects on aquatic and terrestrial ecosystems. Approximately it takes around 1000 years for plastic to degrade, if even degraded it doesn't break completely but into microplastics that absorb toxins and pollute the ecosystem. But this all ends now, as an alternative to plastic is been created with zero pollution.

Seaweeds are photosynthetic algae that are found in different water bodies. Based on the pigment and colouration these are majorly classified into 3 categories namely Green seaweeds (Chlorophyta ) – Cordium fragile, Brown seaweeds (Pheophyta) – Macrocystis integrifolia, and Red seaweeds (Rhodophyta) – Porphyra. Till now, these are used as fertilizers and soil conditioners, animal feeds, fish feeds, biomass, fuel, cosmetics, and so on. As the next level of innovation, a paper “Fabrication and characterization of bio-nanocomposite films using κ-Carrageenan and Kappaphycus alvarezii seaweed for multiple industrial applications” published in the International Journal of Biological Macromolecules has reported the production of biodegradable, edible bags which are produced from seaweeds.

As per the study, the Kappaphycus alvarezii seaweed, commonly known as elkhorn sea moss (red algae) has been used to create bio-nanocomposite films. The addition of metal oxide nanoparticles such as zinc oxide (ZnONPs), cupric oxide (CuONPs), and silicon dioxide (SiO2NPs) altered the surface morphology, increased the roughness, reduced the UV transmission, and water uptake ratio(WUR). By comparing the moisture content and solubility of both standard carrageenan-based bio-nanocomposite films (CBF) and Kappaphycus-based bio-nanocomposite films (KBF) compared to control, the average roughness (Ra) of KBF increased and CBF showed better tensile strength comparatively. By testing the antibacterial activity of both KBF and CBF, the observation has shown antibacterial activity against Staphylococcus aureus and Escherichia coli. Here Kappaphycus- based bio-nanocomposite films showed more activity than carrageenan-based bio-nanocomposite films. However, the antimicrobial properties of the nanoparticles detained the degradation of the films.

 In general, Kappaphycus alvarezii contains carrageenan, a sulfated polysaccharide that is a food additive used to thicken, emulsify, and preserve foods. Carrageenans are known to be safe and allowed as additives by the Food and Drug Administration (FDA) regulations in the USA (Food and Drug Administration, 2018), and by the European Parliament and Council Regulation (EC). The standard of the properties held by the film was compared with the κ-Carrageenan (Kappa-carrageenan) from commercial grade.

Through the study, it has been proposed that these Kappaphycus-based bio-nanocomposite films can be used in various industries instead of PVC plastics. As seaweeds are quickly growing (30- 60 times faster than land-based plants), 5.2-7.2% per day, harvested in a period of 28 days, these are available year-round. When we talk about innovation, it is bound to the concept of sustainability, these seaweed plastics are inexpensive, handy, biodegradable, and constitute zero pollution. 

The TOM FORD Plastic Innovation Prize, a global competition aimed at developing biologically degradable substitutes for conventional thin-film plastic polybags, has announced the winners of 2023 as Sway,  Zerocircle, and Notpla. The $1.2 million prize comprises a combination of cash prize and direct investment presented by Title Sponsors TOM FORD BEAUTY and The Estée Lauder Companies, and Trousdale Ventures, the exclusive venture capital partner of the prize. Although these companies are from different countries, the aim is one, an alternative to plastic bags as seaweed bags.

Nonetheless, with these many benefits, these are still expensive compared with regular plastics. So, the next step is to create them with more compatible methods and make them more available for the industries to replace. And as of, now, scientists are trying to create strips from these seaweeds that can be used for primary packaging.

Reference:

• Muthiyal Prabakaran Sudhakar, Srinivas Venkatnarayanan, Gopal Dharani, Fabrication and characterization of bio-nanocomposite films using κ-Carrageenan and Kappaphycus alvarezii seaweed for multiple industrial applications, International Journal of Biological Macromolecules, Volume219,2022, Pages138-149, SSN0141-8130,https://doi.org/10.1016/j.ijbiomac.2022.07.230.

• TOM FORD Plastic Innovation Prize powered by Lonely Whale.https://plasticprize.org/

• C. Lim, S. Yusoff, C.G. Ng, P.E. Lim, Y.C. Ching, Bioplastic made from seaweed polysaccharides with green production methods, Journal of Environmental Chemical Engineering, Volume9, Issue5,2021,105895, ISSN2213-3437,https://doi.org/10.1016/j.jece.2021.105895.

• Ramya R., Sangeetha Devi R., Manikandan A., Rajesh Kannan V., Standardization of biopolymer production from seaweed associative bacteria, International Journal of Biological Macromolecules, Volume102,2017, Pages550-564, ISSN0141-8130,https://doi.org/10.1016/j.ijbiomac.2017.04.032.

• Handbook of Hydrocolloids, A volume in Woodhead Publishing Series in Food Science, Technology and Nutrition, Third Edition, 2020, Edited by: Glyn O. Phillips and Peter A. Williams.ISBN 978-0-12-820104-6.https://doi.org/10.1016/C2018-0-04245-0

• Plastic Wrap 101 Plastic, Saran, and Cling Wrap Information.https://uspackagingandwrapping.com/plastic-wrap-101.html

• The sticky problem of plastic wrap.Environment story of plastic.National Geographic.https://www.nationalgeographic.com/environment/article/story-of-plastic-sticky-problem-of-plastic-wrap?loggedin=true&rnd=1685196822049