Presentation on theme: "Potentials of Nanotechnologies in Forest and Paper Industry Prof. Yulin Deng School of Chem. & Biomolecular Engineering Georgia Institute of Technology,"— Presentation transcript:
Potentials of Nanotechnologies in Forest and Paper Industry Prof. Yulin Deng School of Chem. & Biomolecular Engineering Georgia Institute of Technology, U.S.A.
Outline of the presentation General Introduction to nanotechnologyGeneral Introduction to nanotechnology Potential applications in forest and paper industryPotential applications in forest and paper industry –Nanofiller Engineering –Superhydrophobic fibers –Barrier coating –Nanostructured papermaking additives Conclusions and ChallengesConclusions and Challenges
What is nanotechnology? Small and Unique Functions! How small? 1 – 100 nm Small is different! 1 nm ~ 5 atoms ~ 1/50,000 width of a human hair Introduction to Nanotechnologies and Nanomaterials How unique? Novel and significantly improved physical, chemical, and biological properties, phenomena, and processes because of their size.
Driving Forces for Nanotechnology Technology expansionTechnology expansion About 90% of all scientific knowledge has been generated over just the last 30 yearsAbout 90% of all scientific knowledge has been generated over just the last 30 years In 1960 < 5% of the general population in North America and Europe had completed 4 or more years of college. In 1999 this increased to ~20%In 1960 < 5% of the general population in North America and Europe had completed 4 or more years of college. In 1999 this increased to ~20% Consumer opinion drivingConsumer opinion driving Demographic analysis indicates that this trend will continueDemographic analysis indicates that this trend will continue Size of the device (nm) Number of devices per chip Neurons in a human brain Kb 64 Kb 1 Mb 16 Mb 256 Mb Road map for microelectronics
Small size makes things different Behavior of Materials at the Nanoscale is NOTHING Like That at the Large Scale Nanoparticles can adsorb UV light and make different colors; Can protect skin from UV exposure Can improve paint scratch resistance Can make heat preservation cloth
Aerogel Silica nanoparticle network Solid with the lowest density (Recorder: 0.02) Heat Resistant Transparent Large specific area
NANO-CARE® fabric protection imparts a revolutionary, carefree quality to wrinkle resistant fabric that minimizes stains, offers superior liquid repellency and maintains wrinkle resistance. Common Day Nano - Applications BC- Applications Mesopotamia 4,500 BC It is nano particles make tires so powerful
Can Macro-Scale Materials Do These? Carbon nanotubes are roughly one hundred times stronger than steel, yet only one sixth the weight! Nano-gear: which can be insert in cells Nanoparticles adsorb on tumor in the body can be imaged.
Nacre (Mother of Pearl) and its equivalent biomimetic structure (left) and anionic montmorillonite layered with a cationic polyelectrolyte (Nature (2003), )
Future Perspectives Forecasting is a “Tricky” Business Wilbur Wright, 1901Wilbur Wright, 1901 –Humans will not fly for another 50 years Thomas Watson, 1943Thomas Watson, 1943 – I envision a world market of about five computers Kenneth Olsen, 1977Kenneth Olsen, 1977 –No one needs to have a personal computer at home Bill Gates, 1981Bill Gates, 1981 –640K will be enough memory for everyone Does nanotechnology has a “ trick ” Future?
What New in Material Science Research Global Nano Technology Research USA ~ $115M~$750M JAPAN ~ $120M~$800M WESTERN EUROPE ~ $125M~$600M OTHER COUNTRIES ~ $ 70M~$750M (FSU, China, Canada, Australia, others) (FSU, China, Canada, Australia, others) TOTAL ~ $430M ~$3000M Potential Economic Impact in years “NANO INSIDE - $ 1 Trillion”
Nano-Patenting Trends Patents containing nano Nano-patents in the exponential phase moving into application development and the second wave of patenting Commercialization potential is broad – multi facilitated field The Business Review – 2003 “Small is big and it's getting bigger”
Times Are Changing Nano-Patents Nano- in the patent: 2812 Quantum in a claim: 1469 Nano in a claim: 195 Nanotechnology in the patent: 148 Nanoparticle in claim: 90 Nanotube in a claim: 60 Nanowire in a claim: 7 1.Discovery of new capability/material 2.Refinement of new capability/material 3.Replacement of old capability/material in old things 4.Invention of completely new things 5.Technology replacement underway
Bottom-up: atom-by-atom engineering using the tip of a scanning probe Outstanding problems: - “Fat finger” problem - “Sticking finger” problem - Building rate – really slow! If a device size is 5 nm and the building speed of an SPM is 10 9 atom/s, it will take 6 months to build devices on a 8” wafer.
50 Device size (nm) 100 Time Bottom up: atom engineering (Science) Top down (MEMS) (engineering) Nanotechnology Future of nanotechnology
Self Assembly of Molecules on a substrate
Potential applications in forest and paper industry
Unlimited Areas Nanofiberils Nanocomposites Inkjet printing & laser printing Barrier Coating Nanostructured funcational polymer Nanostructured fillers Nanotechnology of Forest Special papers Smart Packaging E-ink, power ink and other chemicals Nano Biology Nano Sensors
Nanotechnology in Forest and Paper Industry A roadmap of Towards a European Strategy for Nanotechnology was developed in Brusseles, May, 2004, Commission of the European CommunitiesA roadmap of Towards a European Strategy for Nanotechnology was developed in Brusseles, May, 2004, Commission of the European Communities A roadmap of Nanotechnolgy for U.S. Forest was developed in 2005A roadmap of Nanotechnolgy for U.S. Forest was developed in 2005 Several conferences, such as nanotech for paper workshop, smart pakage workshop, were organizedSeveral conferences, such as nanotech for paper workshop, smart pakage workshop, were organized
Major Nanotechnology Domains Identified for the Forest Products Sector (U.S. Workshop of Nano for Forest) Nanocomposite/composite cellulosic materialsNanocomposite/composite cellulosic materials SelfassemblingSelfassembling Nanostructure of fiber wallNanostructure of fiber wall Nanoanalytical toolsNanoanalytical tools NanosensoringNanosensoring
Nano-Hemicelluloses For Barrier/Strength Improvements AFM of nanoxylan - Strength Benefits Under Study - Barrier Properties Reported Glucomannans Unexplored
Hierarchical Structure of Paper Paper Properties Paper making, refining fiber mixtures, papermaking chemicals, fillers Molecular Lignin/cellulose/hemicellulose, Cellulose crystallinity/fibrils Hydrogen Bonds, Acid-base Interactions Fiber Wall Fiber-wall thickness/layers, Cellulose fibril angle Fiber Fiber type & dimension, Propensity for fiber collapse, Curl/kinks, Fiber strength Fiber Network Bonding between fibers and response to refining nm Fiber Scale mm
Do we know enough about the nanostructure of wood fibers? Make recycled fiber interchangeable with virgin fiber with respect to product quality and economics allowing competition with virgin fiber on all metrics: availability, strength potential, quality, processing performance and cost. Never dry fiberDry and re-swelled fiber
State of Papermaking Time to re-engineer from Bottom-Up! Engineering has dramatically Improved Sheet Quality The Process
Super-hydrophobic Barrier Coating Method of enhancing hydrophibicity: Lowering surface energy by coating of hydrophobic material. However, even materials with the lowest surface energy (6.7 mJ/m 2 for a surface with regularly aligned closest-hexagonal-packed –CF3 groups) gives a water contact angle of only around 120 o. Super-hydrophobic surface: Both receding and advanced water contact angles above 150 o. Water, ice, grease, and bio contaminants will not be able to deposit on super-hydrophobic surfaces
Figure 1. (a) SEM images of the lotus leaf surface. Schematic representation of the self-cleaning mechanism: moving of water droplet along contaminated smooth (b) and rough (c) surfaces. (c)(b) (a) Lotus Effect
Super-hydrophobic surface with nanofibers Figure 2. SEM images of a) surface of the polyacrylonitrile (PAN) nanofibers; b) cross-sectional view of the PAN nanofibers. Figure 3. Shapes of water droplets on a) the PAN nanofibers with a rough surface; b) the native PAN film with smooth surface. Li Jiang, et al, “Super-Hydrophobic Surface of Aligned Polyacrylonitrile Nanofibers” Angew Chemie Intl Ed 2002, 41, 1221.
Coatings with hydrophobic silica (colloidal silica + FAS-17) Figure 4. SEM images of films on glass and the shapes of water droplets on the films. (a) glass + heptadecafluorodecyltrimethoxysilan (FAS-17) coating; (b) film from methanol based colloidal silica and (c) film from methyl ethyl ketone (MEK) based silica. T. Watanabe, et al, “Processing of roughened silica film by coagulated colloidal silica for super-dydrophobic coatng” J Materials Sci Lett 2001, 20, 1975.
Applications Commodity applications –Self-clean glass (car windshield, glasses, china, etc.) –Swim and diving suits –Self-clear clothes –Food package, cups and food plates High technology applications –Anti-frost aircraft –Boat, ship, submarine –(long life and fast) –Spaceship
Vijay Mathur, 2004 TAPPI Paper Summit, May 3-5, 2004, atlanta, GA, USA Nanostructured Filler Engineering Nanosilicate Fibril Fillers
Nanostructured Filler Engineering: Mg(OH) 2 Nanobelts synthesized by our group Low cost Low density (2.4) High brightness No retention aid is needed (good formation) Less effects on paper strength Good candidate for polymer reinforcement
Barrier Coating with Nanomaterials Polymer-clay nanohybrids are important new materialsPolymer-clay nanohybrids are important new materials –Improve modules, scratch properties, strength, stiffness, heat resistance and preservation, etc. –Increase barrier properties for gas, water and grease –Can be used for textile, painting, coating, and many others Barrier properties are very important for some paper products, such as containers for milk, juice, ice cream, meet, fish, fruit, microwave fast food, food plates and boxes, drink cups, photo papers, etcBarrier properties are very important for some paper products, such as containers for milk, juice, ice cream, meet, fish, fruit, microwave fast food, food plates and boxes, drink cups, photo papers, etc Problems of waxed food containers: un-recyclable, cannot be used as containers for milk, juice, ice cream, fast food, food platesProblems of waxed food containers: un-recyclable, cannot be used as containers for milk, juice, ice cream, fast food, food plates
Polymer-Nanoclay Composites The thickness of nanoclay in the composite is about 1nm. Barrier coating for food containers and paper packages Water and vapor resistance, fatty and oil resistance, board strength
Synthesis of polymer-nanoclay composite Cationic SurfactantMonomer Polymer Cation exchange by Intercalation Monomerpenetration ExfoliationPolymerization
Key Issues Using Polymer- Nanoclay for Barrier Coating Water BasedWater Based –Emulsion/miniemulsion polymerization Uniformed Distribution (no aggregates in the polymer matrix)Uniformed Distribution (no aggregates in the polymer matrix) –Correctly using surfactant Strong affinity between polymer and nanoclayStrong affinity between polymer and nanoclay –Seeding and modification technology EconomicEconomic –Using bentonite (Kaolin clay cannot be exfoliated) H2OH2O The products are not available
Composites for Coating Water-based polymer-clay nanohybrid suspension is not available Encapsulation of clay in polymer latex has been unsuccessful Encapsulated clay has to be exfoliated to 1-2 nm by polymer, which makes the process being more difficult H2OH2OH2OH2O Polymer latex Exfoliated clay
Polymer-Nanoclay Composites Why have to be nano? One bentonite particle can split in to layers If 3% of nanoclay is needed, which equals 90% (= 3%x30) of large clay if the surface area is kept the same.
Nanosilicate Sol: Paper Retention system Stable CaCO 3 filler in water Addition of liner cationic polymer flocculant Addition of nano silicate sol (1-10nm) Soft, large floc Hard, dense floc Have been used in paper industry more than 20 years!
Nanoparticle Flocculant Systems Improves papermaking process and paper properties (high retention, small floc size, fast water drainage, uniform paper formation)Improves papermaking process and paper properties (high retention, small floc size, fast water drainage, uniform paper formation) Negatively charged nanoparticles, such as silica sol-gel and bentoniteNegatively charged nanoparticles, such as silica sol-gel and bentonite Used with a high MW cationic water-soluble polymerUsed with a high MW cationic water-soluble polymer The smaller the particle size, the higher the retention efficiencyThe smaller the particle size, the higher the retention efficiency Improves papermaking process and paper properties (high retention, small floc size, fast water drainage, uniform paper formation)Improves papermaking process and paper properties (high retention, small floc size, fast water drainage, uniform paper formation) Negatively charged nanoparticles, such as silica sol-gel and bentoniteNegatively charged nanoparticles, such as silica sol-gel and bentonite Used with a high MW cationic water-soluble polymerUsed with a high MW cationic water-soluble polymer The smaller the particle size, the higher the retention efficiencyThe smaller the particle size, the higher the retention efficiency
Cationic Nanoparticle Retention Aids
Conclusion and Future Challenges Nanotechnology will change our life in the future. Nanotechnology has unpredicted impact on forest and paper industry We are not starting from zero – Many nanomaterials and nanotechnologies have been used in industries and our day life –Many novel materials have been developed and fundamental studied have been done in broad research areas –We have very powerful tools today than before There are many challenges –The cost of nanomaterials is high –We are not able to fully control the structure of wood fibers, inorganic fillers and polymers –Paper and forest industries are classic industries. Not many research scientists conduct research in nano areas –We need both high educated people and research funds –Economics, health and environmental effects and social studies have not been studied