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Nanocomposites of Cellulose For Medical Application

Nanocomposites of Cellulose For Medical Application. Asif Rasheed Lecturer, Department of Chemistry University of Wisconsin, Whitewater 800 West Main Street, Whitewater, WI 53190 rasheeda@uww.edu. Cellulose:. The most abundant, biodegradable and biocompatible polymer

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Nanocomposites of Cellulose For Medical Application

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  1. Nanocomposites of Cellulose For Medical Application Asif Rasheed Lecturer, Department of Chemistry University of Wisconsin, Whitewater 800 West Main Street, Whitewater, WI 53190 rasheeda@uww.edu

  2. Cellulose: The most abundant, biodegradable and biocompatible polymer Applications include fiber, paper, membrane, polymer and paint industries Tissue engineering Nanocomposites Strong intra and intermolecular hydrogen bonding hence difficult for processing H - bonding is reduced by partial replacement of hydroxyl groups, this process involves complex multiple steps and uses toxic chemicals => Conern to Environment Effect on Nano-filler

  3. Cellulose Dissolution • Ionic Liquid: Able to break down H-bonding in biopolymers, hence can dissolve biopolymers e.g. cellulose and silk 1-ethyl-3-methylimidazolium acetate (EMI acetate) Cellulose pulp paper (Grade V-60) from Buckeye Technologies Inc. Degree of Polymerization ~ 820 Control cellulose film regenerated from ionic liquid

  4. Composites of cellulose and vapor grown carbon nanofiber (VGCNF) and carbon nanotubes • Composites of cellulose and hydroxyapatite (HAP)

  5. 1) Cellulose-CNT Nanocomposite SWNT MWNT VGCNF • Young’s Modulus ~ 1 TPa • Electrical Conductivity • ~ 100 times Stronger than Steel at 1/6th of weight • Thermal Conductivity

  6. Previous Experience with Polyacrylonitrile (PAN)/VGCNF Nanocomposites Mechanical Properties Electrical Conductivity Thermal Stability Experimental and theoretical specific modulus of various PAN/VGCNF composite films assuming the modulus of VGCNF to be 50 GPa. (a) Experimental modulus, (b) theoretical modulus assuming VGCNF length to be 0.2 m, (c) 1 m, (d) 10 m and (e) 100 m. Electrical conductivity of PAN/VGCNF composite films. Tan δ (below) as a function of temperature for (a) Control PAN, (b) PAN/5%VGCNF, (c) PAN/10%VGNCF, (d) PAN/20%VGCNF, (e) PAN/40%VGCNF and (f) PAN/90%VGCNF composite films. Guo, H.; Rasheed, A.; Kumar, Satish J Mater Sci (2008) 43:4363-4369

  7. Incorporation of a nano-filler (SWNT, MWNT, VGCNF) into cellulose matrix is expected to • Enhance tensile strength and tensile modulus • Impart thermal stability • Reduce shrinkage (dimensional stability) • Result in electrical conductivity in the nanocomposite • Electroactive paper • Actuators/sensors • Medical Devices Cellulose+5%VGCNF

  8. 2) Cellulose/Hydroxyapatite Nanocomposites • Hydroxyapatite (HAP) Ca10(PO4)6(OH)2 finds many applications as bio-material • Filler to replace amputated bone • Coated to promote bone in-growth into prosthetic implants • Cellulose Hydroxyapatite composites have great potential to be used in bone tissue engineering

  9. Previous Reports: Cellulose/HAP Composites • Precipitated on cellulose in-situ from aqueous solution* • Deposition of HAP limited to surface • The process is extensively long (up to ~14 days) to prepare the composite Current Approach • Homogenous dispersion of HAP in cellulose matrix • Fast processing • Composition of composite can be easily varied Cellulose+10% HAP Cellulose+60% HAP *Materials Letters 60 (2006) 1710-1713 Hong, L.; Wang Y. L.; Jia, S. R.; Huang, C. G.; Wan, Y. Z. 2005. Hydroxyapatite/bacterial Cellulose Composites Synthesized via Biomimetic Route. Materials Letter. 60:1710-1713

  10. Acknowledgments • Students (Peter Zastraw, Matthew Magruder, Travis Martin) • Prof. Peter Jacobs (Geology Department, UW-Whitewater) for XRD • UW-Whitewater for funding • Department of Chemistry, UW-Whitewater

  11. Cellulose/HAP Composites: XRD Testing for biocompatibility

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