Today, the growing demand for the manufacturing and production of sustainable and compostable materials and technologies is directly related to the pressing threat of how our daily choices affect climate change on a global scale.
Biomaterials, which describe any engineered substance that originates from a natural source and is applied for various technical applications, have been at the forefront of this transition to more ecologically conscious technologies. To advance this effort, a group of Researchers led by Jeffrey Catchmark at the College of Agricultural Sciences in Pennsylvania State University have developed an inexpensive polysaccharide nanocellulose biomaterial that could eliminate the use of plastics completely.
Most often produced homogenized wood pulp or other plant matter, nanocellulose is a psuedoplastic fibrillar cellulosic material that contains dimensions measuring in the range of 5-20 nanometers (nm). The applications of nanocellulose are innumerable, and can be found within the medical, food and pharmaceutical industries to ameliorate existing products, such as food packaging, sensors, paper, components of oil, antimicrobial films or water absorbent pads1.
This lightweight and completely non-toxic material is a desirable additive to their given products within these industries as a result of their unique nanoscale properties and characteristics. Some of which include a tensile strength that can measure eight times greater than that of steel, high absorbent potential, transparency and impermeability to gas. As a derivative of cellulose, the most abundant polymer on earth, the production of nanocellulose material is also an extremely cost-effective alternative to traditional plastic materials.
The Penn State Researchers utilized the carboxymethyl nanocellulose (CMC) type, which is otherwise commonly known as cellulose nanocrystals, in their study. Extracted through the acid hydrolysis of cellulose fibers, CMC is a rigid, rod-like nanomaterial that can be derived from several types of natural sources including wood, algae, plants and bacteria.
With several applications already found in aerogels, foams, nanocomposites, supercapacitors and other functional material, CNC has been found to dramatically improve certain material properties for such applications. These properties include viscosity control, water solubility, immiscibility in oil and organic solvents, and several others. By combining this durable material to chitosan, which is a natural derivative of the exoskeleton, chitin, that is present in various crustaceans, was shown by Catchmark’s team to produce an unexpectedly strong film for packaging applications.
As two materials that are already actively used in several industries, chitosan and CMC possess opposing molecular charges, however, this difference makes them ideal candidates for the strong and stable structure required for coatings, films and adhesives2. The electrostatic complex in the chitosan/CMC structure produces an environmentally friendly barrier coating that is simultaneously water resistant, thereby allowing for its potential use to be practical for applications outside of food storage containers and spreading to wallboard and ceiling tiles.
Within the food industry, this chitosan/CMC material’s utter safety is also a desirable property, completely eliminating any potential contamination of food products, such as that which can occur through plastic containers containing the harmful chemical bisphenol A (BPA).
Globally, it is estimated that 300 million tons of plastic is produced each year, which accounts for more than 29 million tons of waste that originates from purely plastic products. As this waste continues to accumulate, it is becoming a pressing concern when such residual debris affects the safety and preservation of our oceans and environment.
The chitosan/CMC material developed in this study has the potential to reduce these harmful pollution effects by completely replacing the millions of petroleum-based plastic packaging that are used around the world each day. Before this can occur, the Researchers must focus their endeavors on ways in which this biomaterial can be mass-produced in a rapid and cost-effective manner to cater to the global needs.
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- “What is Nanocellulose?”
- “New biomaterial could replace plastic laminates, greatly reduce pollution” – Penn State News