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|Sunday, 04 July 2010|
Nature has created many majestic materials. Cellulose is the most abundant organic compound on our planet. Derived from nature's novel biopolymer, Nano Crystalline Cellulose (NCC) is one of the strongest materials ever known to human. NCC is extracted from woody biomass using controlled acid hydrolysis. Scientists in Canada have pioneered the investigation, modification and synthesis of cellulose nanocrystals to develop advanced materials and sophisticated solutions for challenging applications. This research reveals challenges and opportunities with super strong nanocrystalline cellulose synthesis in perspective.
All plant materials contain at least 20% to 50% cellulose. Composed of long chains of glucose molecules, the intricate web of crystalline and amorphous regions of cellulose supports the structural cells and physical features. The crystalline region provides the strength and rigidity while the amorphous region yields the elasticity and flexibility. Recent advances in bio, nano and textile technology enable us restructuring the structural formation of materials to produce lightweight (specific gravity) super strong (tenacity, strength at break) tough (modulus, resistance to extension) materials with superior performance and functional physical features.
Cellulose whiskers or nanocrystals are produced by controlled strong sulphuric acid (H2SO4) hydrolysis by breaking down the cellulose fibrous assemblies, (acid predominantly attacks the disordered amorphous regions) and isolating highly oriented crystalline regions. Algal, Bacteria, Cotton, Flax, Hemp, Jute, Tunicate and Wood are unique sources of green nanoparticles. Among them, wood-pulp based NCC show high promise. NCC exhibits many attractive physical properties and functional features: exceptional mechanical properties, biodegradable, biocompatible, non-toxic, sustainable and recyclable.
Typical Properties of Wood-based NanoCrystalline Cellulose:
Nature presents diverse variation in the feedstock. The best quality jute we get in Bangladesh.
Integration of nano-sized 10-75nm carbon particle fillers into the rubber matrix increases the strength 1000x, stiffness 7x and abrasion resistance 5x folds. Tires would not be made from rubbers without carbon black fillers. Cellulose nanocrystals offer similar challenging opportunities:
A few examples of prospective applications:
FP Innovations, Canada, currently produce kilogram quantities of wood NCC, are working with NORAM Engineering to design a 1 ton/day facility - expected to be operational within 1 year.
Cute Jute NCC?
Scientists in Bangladesh have recently cracked the genetic sequence code of jute. Once jute was well-known as the golden fiber of Bangladesh. Jute has 60-65% cellulose. The modification of materials and synthesis of highly oriented nanocrystalline structures are expected to revive jute again for developing specialty products with critical performance requirements.
Bulk gold is yellow. Nano gold is red. Due to high surface area, nano materials have lower melting point than the bulk materials. Although much more research and innovation are necessary to further improve the synthesis, modification and characterization of materials, it is already clear that nano-crystalline cellulose possess a number of promising physical properties. Facing the fascinating challenges, until further advances are achieved, scientists must turn to nature to culture nature's nanoscience.
National Science Foundation, NSF, predicts that nanotechnology will boost the U.S. Economy by US$1 trillion a year by 2015. The NSF expert panel also projects, "The effect of nanotechnology on this century could be at least as significant as the combined influences of microelectronic, medical imaging, computer aided engineering and man-made polymers developed in the past century." Nanocrystalline Cellulose has yet to make an impact on the marketplace.
Stay tuned. More to come....
Acknowledgements: TexTek Solutions :: MW Canada Material Innovations.
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