{"id":25444,"date":"2018-07-27T10:15:30","date_gmt":"2018-07-27T14:15:30","guid":{"rendered":"https:\/\/www.tun.com\/blog\/?p=25444"},"modified":"2022-03-16T10:38:57","modified_gmt":"2022-03-16T14:38:57","slug":"crab-shells-trees-replace-plastic-packaging","status":"publish","type":"post","link":"https:\/\/www.tun.com\/blog\/crab-shells-trees-replace-plastic-packaging\/","title":{"rendered":"Material Made From Crab Shells, Trees Could Replace Plastic Packaging"},"content":{"rendered":"

An environmentally sustainable material <\/span>derived from crab shells and tree fibers<\/span><\/a> could replace flexible plastic packaging used to keep food fresh, according to new research from Georgia Institute of Technology. <\/span><\/p>\n

The researchers have developed a method to spray multiple layers of chitin from crab shells and cellulose from trees to form a flexible film similar to plastic packaging. <\/span><\/p>\n

The research comes at a time when the market for consumer products made of sustainable and renewable resources is increasingly growing. <\/span><\/p>\n

The research is published in the journal <\/span>ACS Sustainable Chemistry and Engineering<\/span><\/a>. <\/span><\/p>\n

Inspired by natural materials <\/b><\/h2>\n

The researchers began working on the material after finding inspiration from cellulose nanocrystals and chitin nanofibers in their previous work. <\/span><\/p>\n

The materials are two of the most common natural biopolymers — cellulose, which comes from plants, is the most common, followed by chitin, which is found in shellfish, insects and fungi. <\/span><\/p>\n

\u201cWe had been looking at cellulose nanocrystals for several years and exploring ways to improve those for use in lightweight composites as well as food packaging, because of the huge market opportunity for renewable and compostable packaging, and how important food packaging overall is going to be as the population continues to grow,\u201d <\/span>J. Carson Meredith<\/span><\/a>, a professor in Georgia Tech\u2019s School of Chemical and Biomolecular Engineering, said in a statement.<\/span><\/p>\n

They were investigating chitin for an unrelated reason when they had the idea to merge the two together. <\/span><\/p>\n

\u201cOur original interest was inspired by an insect called the white beetle, where the outer forewing made of chitin is a brilliant white color,\u201d said Meredith. <\/span><\/p>\n

\u201c<\/span>We were trying to copy this white color in a renewable material, but found that we could make nice transparent films too.\u201d <\/span><\/p>\n

They recognized that chitin nanofibers are positively charged and cellulose nanocrystals are negatively charged and decided to test the two as alternating layers in a coating. <\/span><\/p>\n

\u201cThey complement one another in forming a dense, impenetrable structure because they are both crystalline and they are oppositely charged. There are studies that indicate these will compost well together (once they are discarded),\u201d said Meredith. <\/span><\/p>\n

Developing the product <\/b><\/h2>\n

The team developed a method to create a film by suspending cellulose and chitin nanofibers in water and spraying them onto a surface in alternating layers. <\/span><\/p>\n

Once the material is fully dried, the result is a flexible, strong, transparent and compostable film. <\/span><\/p>\n

Not only does it mimic physical properties of plastic film, but it also provides a better gas barrier that prevents oxygen from escaping, according to the researchers. <\/span><\/p>\n

Food packaging needs to prevent oxygen from passing through in order to preserve food, and the researchers found that the crystalline structure of the film creates a better barrier to prevent gas from escaping. <\/span><\/p>\n

\u201cIt\u2019s difficult for a gas molecule to penetrate a solid crystal, because it has to disrupt the crystal structure,\u201d Meredith said in a statement. \u201cSomething like PET [<\/span>polyethylene terephthalate] <\/span>on the other hand has a significant amount of amorphous or non-crystalline content, so there are more paths easier for a small gas molecule to find its way through.\u201d<\/span><\/p>\n