67 %
33 %
Information about GRD MatE

Published on January 22, 2008

Author: Siro


Geetha R Dholakia NASA Ames Research Center :  Geetha R Dholakia NASA Ames Research Center April 26, 2006 San Jose State University Applications of Nano Materials Relevance for Aerospace Slide2:  Changes in properties due to change in size: Electronic properties, band gap etc. Material properties scaling due to size. Tensile strength, thermal conductivity etc. Higher order properties of nanostructures: Self assembly, superlattices etc. Properties of Nanomaterials Slide3:  Nanoscale objects and their properties Nanoparticles Nanotubes Nanowires Nanoscale films and coatings Self assembled systems Composites Slide4:  NASA’s Requirements Ultrasmall sensors, power sources. Low mass, volume and power systems. For communication, navigation and propulsion. Slide5:  NASA Nanotechnology Roadmap Credits:NACNT Slide6:  MOLECULE LUMO HOMO CB VB Eg Energy NANOPARTICLE Eg Eg BULK SEMICONDUCTOR Energy Level Diagram: Quantum Size Effects Slide7:  Quantum size effects: Noble metals, Semiconductors, Oxides. Engineer Eg over a wide spectral range: IR to UV. Semiconductor Q Dots: II-VI: CdS, CdTe, CdSe, PbS, ZnSe PbS: Eg:0.41 eV 2.34 eV. (300K, 15 nm) (300K, 1.3 nm) Eg of PbS nanoparticle vs particle size Nanoparticles: Quantum Size Effects Wang et al. J. Chem. Phys. 87, 12 (1987). Slide8:  CdSe quantum dots Semiconducting CdSe nanodots: Illumination with a single light source Emission shifts to higher energy with decreasing particle size. Metallic Au nanodots: Fluorescence shifts to longer  (lower energy) with increasing nanocluster size. J. Zheng et al, Phys. Rev. Lett. 93, 077402 (2004). J.L. West and N. Halas, Ann. Rev. BioMed. Eng. 5, 285 (2003). Nanoparticles: Quantum Size Effects Au Nanoclusters Slide9:  Applications of nanoparticles: Astronaut Health and Biomedical Applications Apollo 11 mission took 8 days 3 hrs and 18 min. July 16-24, 1969. Travel time to Mars ~ 8 months one way. Astronauts will be exposed to effects of space radiation. Biocompatible Q Dots are used for diagnostic imaging of cells. Cancer cells can be targeted by adding antibodies to Q Dots which specifically bind to cancer cells. B. Dubertret et al. Science, 298, 1759 (2002). Apollo 11 Mission Imaging cells and drug delivery Slide10:  Applications of nanoparticles:Solar Cells Conventional inorganic solar cells: Efficiency ~ 10-30%. Downside: High fab cost. (high Ts, high vacuum, expensive litho.) Organic solar cells: Low fab cost. Downside: Efficiency ~ 2 –5 % Alternatives: Hybrid dye sensitized Q dot and nanorod-polymer solar cells (TiO2, CdSe). Spirit after two years Slide11:  Carbon Nanotubes: Graphene Sheets to Nanotubes d: 1.2 nm From “Electronic Structure of Carbon Nanotubes” by L. C. Venema, Delft Univ. Press. Slide12:  P. G. Collins and Ph. Avouris, Scientific American, 283, 62 (2000). Carbon Nanotubes: Electronic Properties Slide13:  Carbon Nanotubes: Energy gap of SWCNTs J. W. G. Wildoer et al., Nature, 391, 59 (1998). Eg of CNT vs tube diameter Slide14:  Nanomaterials growth: VLS Growth of Nanowires Example: Ge nanowire growth Slide15:  D.D.D. Ma et al., Science, 299, 1874 (2003). Nanowires: Energy gap of Si Nanowires as a function of diameter Size Tunable Band Gap Slide16:  Applications of Nanotubes Nanoelectronic Devices: CNTs as FETs Slide17:  Y. Huang et al., Nano Lett., 2, 101 (2002). Applications of Nanowires Nanoelectronic Devices: GaN Nanowires as FETs Slide18:  J. A. Misewich et al., Science, 300, 783 (2003). Applications of Nanotubes Photonic Devices: SWCNT IR emitter Slide19:  Applications of Nanowires Photonic Devices: p-si\n-GaN UV Nano LED C. M. Lieber et al., Small, 1, 142 (2005). Slide20:  A. Modi et al., Nature, 424, 171 (2003). NanoSensors and Detectors: Nanotube Based Gas Sensing Application: Toxic gas detection and removal in life support systems in space vehicles. Slide21:  J. Robertson, Materials Today, 46 Oct 2004. Instrumentation: Nanotube Based Field Emitters W. B. Choi et al., Appl. Phys. Lett, 75, 3129 (1999). Slide22:  Instrumentation: Nanotube X Ray Tubes Chemical and Mineralogical Analysis Of Martian Rocks PI Dr. D. Blake NASA Ames Slide23:  Other Aerospace Applications of Nanomaterials Based on enhanced tensile strength, thermal conductivity and other nano material properties. Nanocomposites: Self healing nanofiber, CNT, polymer, ceramic or metal matrix based composites. Lightwitght structures for spacecraft. Thermal protection systems and Radiation shielding. Entry temperatures: 200-1500o C. Credits:NASA Slide24:  Nanopowders for Solid-propellant rockets: Aluminium or boron oxide nanopowders. Increased surface area of the nanopowders enhances thrust. Aerogels: Thermal isolation material in the Mars Rover of the Pathfinder mission, Particle collector in the NASA Stardust mission. High strength, ultra-light structure materials for spacecraft. Other Aerospace Applications of Nanomaterials Credits:JPL Slide25: Nanoroadmap: Technological and Economic Aspects Slide26:  Thank you all.

Add a comment

Related presentations

Related pages

GRD-MatE - Ace Recommendation Platform - 1

MatE297 Guest Lecture / GR DholakiaGeetha R DholakiaNASA Ames Research CenterApril 26, 2006San Jose State UniversityApplications of Nano Materials ...
Read more

Akademischer Grad – Wikipedia

Akademische Grade sind Abschlussbezeichnungen, die von Hochschulen aufgrund eines erfolgreich abgeschlossenen Studiums oder aufgrund einer besonderen ...
Read more

Papermate -

papermate flair pt grd sky blue upc. $3.76. qty . add to cart. papermate flair pt grd purple upc. ... paper mate flair pt grd magenta upc. product code ...
Read more

Last Year S Grd 9 Maths Last Term Memorundum

Download and Read Last Year S Grd 9 Maths Last Term Memorundum. Title Type maths mate term 3 sheet 8 answers PDF maths mate 8 answers term 2 sheet 5 PDF
Read more

Study Mate - Scribd

Stressed out about your school work? Don’t panic, Study Mate is here to help! Keep up to date with the latest matric news in Study Mate.
Read more

Paper Mate Flair Felt Tip Pens, Medium Point, Red, 12-Count : Paper Mate Flair Felt Tip Pens, Medium Point, Red, 12-Count : Flair Pens : Office Products
Read more

Mag-Mate Magnetic Weld Angle w/Grd, 3-2/5in, 150lb ...

Order MAG-MATE Magnetic Weld Angle w/Grd, 3-2/5in, 150lb, WSS300MS at Great prices & free shipping on orders over $50!
Read more

Mag-Mate Magnetic Weld Angle w/Grd, 4in, 150lb WSM0150RG ...

Order MAG-MATE Magnetic Weld Angle w/Grd, 4in, 150lb, WSM0150RG at Great prices & free shipping on orders over $50!
Read more

Springfld Grd, New York Criminal Records

Springfld Grd, New York Criminal Records. Criminal records and background checks may be available for individuals living in Springfld Grd or the ...
Read more