Sunday 4 July 2010

Super Strong NanoCrystalline Cellulose Synthesis: Challenges and Opportunities

Super Strong NanoCrystalline Cellulose Synthesis: Challenges and Opportunities


 | ন্যানোপ্রযুক্তি| লিখেছেন  ৩ comments       
Sunday, 04 July 2010
 
Dedicated to: Dr. Mustafizur Rahman, Head of the Department, Textile Engineering & Technology, AUST, Dhaka.
 
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.
 
Introduction:

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:
  • Rod-like shape. Aspect Ratio (D:L): 1 to 100. Yield 10-30%.
  • Typical Length (L) x Diameter (D): 200nm x 10nm (1nm = one billionth of 1m).
  • Tensile Strength Ts: 10 GPa (Steel: 1.28 GPa) (1 GPa = 100kg/mm2).
  • Elastic Modulus Em: 150 GPa  (Steel: 210 GPa).
  • Total Performance Ts x Em: 1500 GPa (Steel: 268.8 GPa).
  • High Surface Area: 250 m2/g.
  • Specific Gravity: 1.5 g/cc? - very light compared to Steel: 7.8 g/cc. (Water: 1 g/cc).
  • Cellulose Content in Wood / Straw: 40-50%.
  • Good Optical Properties - Create Colours without Dye or Pigment.
  • Self-assembly, Self-cleaning, Antibacterial, Conductive.
  • Biodegradable, Biocompatible, Non-toxic, Recyclable, Renewable, Sustainable, Eco-friendly
  • Cost-effective.
NCC's extraordinary physical properties are of attractive choice for many demanding applications. 
 
Challenges:
Nature presents diverse variation in the feedstock. The best quality jute we get in Bangladesh.
  • Selecting the right species of cellulose (feedstock)
  • Consistency of the feedstock building blocks
  • Time dependent integrity of polymer
  • Dispersion and orientation of nanoparticles
  • Cohesiveness and bonding filler and matrix
  • Transfer load to reinforcing filler
  • Carry and share load between broken and intact filler particles
  • Understanding nanomaterial synthesis, design, modification and characterization of materials
  • Improving interdisciplinary knowledge for intelligent design of products
  • Integrate physical properties of nanomaterials for futuristic functional features
  • Effective yields and chemical recovery
 
Opportunities:
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:
  • Replace petrochemical based materials
  • Develop lighter, safer, stronger materials
  • Recyclable components for renewable resources
  • Produce conductive materials from non-metallic nano-particles
  • Research and modify jute and other cellulose nanocrystal structures
As the size of the particle reduces the degree of defects reduces and mechanical properties improves significantly. Even small additions of NCC fillers to polymer matrix can increase its strength exponentially. Just "by adding an ounce of NCC to a pound of plastic, you can increase the strength of plastic by 3000x times," reported Dr. William T. Winter, a chemistry professor and director of the Cellulose Research Institute at ESF, USA. 
 
Applications:
A few examples of prospective applications:
  • Advanced reinforced polymers, adhesives, bioplastics and nanocomposites
  • High performance textile fiberous and structural materials
  • Barrier films and membranes with superior physical properties and functional feature
  • Tissue engineering, heart valves, skin grafts bone replacement and tooth repair materials
  • Pharmaceuticals, antibacterial products and drug delivery
  • Sensors, actuators and switchable optical devices
  • Additives for coatings, paints, food and cosmetics
  • Improved paper packaging and construction products
  • Automotive, aerospace and transportation
Achievements:
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.
 
Conclusion:

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. 
 
Further References: 
2011 Forestry sector lays the roots for a future in bioproducts - The ...
2011 Nanocellulose plant inaugurated | Pulp & Paper
2010 Pulp and Paper Canada - Nanocellulose steps up on stage
2010 Iridescent Solid NanoCrystalline Cellulose Films Incorporating Patterns and Medthod for Their Production, S Beck, J Bouchard, R Berry, USP 2010/0151159 A1, Jun 17
2010 Technical Interactions, R Berry, FP Innovations, Montreal, Canada.
2010 Parameters Affecting the Chiral Nematic Phase of NanoCrystalline Cellulose Films, J Pan, W Hamad, S K Straus, Macromolecules, 43, 3851-3858
2009 Canada Strikes Nanotech Gold, R Lombardi, Canadian Business Online, Oct 13
2009 New Wood-Fibre Product Holds Promise for Forestry Industry, Edmonton Journal, Jun 25
2009 A Technique for Production of Nanocrystalline Cellulose with a Narrow Size Distribution, W Bai, J Holbery, K Li, Cellulose, 16, 455-465 
2006 Cellulose NanoCrystals Make Plastic 3,000 Times Stronger, Nanowerk News, Oct 19 
2006 Methods and apparatus for spinning spider silk protein, S Islam et al., USP 7,057,023 Jun 6
2005 High-toughness Spider Silk Fibers Spun from Soluble rc-Silk Produced in Mammalian Cells, C Karatzas, S Islam et al., Biotechnology of Biopolymers: From Synthesis to Patents, 2 Volumes, Germany 945-966
2005 Nanotech Changes Everything, R Spence, Canadian Business Online, Jul 25
2005 Value-added Textile Technology, S Islam, Textile Excellence J., Anniversary Issue, Jul. 3(1) 55-56

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মন্তব্যগুলো (3)Add Comment

Cellulose Nanocrystals of cute Jute
লিখেছেন salmaAkter, July 04, 2010
অপেক্ষায় আছি জানার জন্ন্য।

...
লিখেছেন shampa, October 13, 2010
banglay lakha chai.

Super Strong NanoCrystalline Cellulose Synthesis: Challenges and Opportunities


লিখেছেন Shafiul Islam, October 13, 2010
Shampa,
Thanks for your thoughts. May I request you to translate this article?
:)
শফিউল


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