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CHE5480 Summer 2005. Nanostructures: Introduction. TOPICS:. Theory: (Dr. Lee) Experiments (Dr. Newman) Computer: (Dr. Neeman) Attending Nanotechnology Meeting. What size is a nanometer?. A nanometer (nm) is 10 -10 meter (1 m = 3.28 ft). Nanotech: from1 nm to ~100 nm Albumin 6.5 nm

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che5480 summer 2005

CHE5480 Summer 2005

Nanostructures: Introduction

topics
TOPICS:
  • Theory: (Dr. Lee)
  • Experiments (Dr. Newman)
  • Computer: (Dr. Neeman)
  • Attending Nanotechnology Meeting
what size is a nanometer
What size is a nanometer?
  • A nanometer (nm) is 10-10 meter (1 m = 3.28 ft).

Nanotech: from1 nm to ~100 nm

Albumin 6.5 nm

Ribosome 25 nm

Argon 0.3 nm

CH4 0.4 nm

H2O 0.3 nm

Red Blood Cell 2000x7000 nm

what size is a nanometer 2
What size is a nanometer? (2)

HIV virus 125 nm

Red Blood Cell 2000x7000 nm

Argon 0.3 nm

CH4 0.4 nm

H2O 0.3 nm

~1 nm ~100 nm

Albumin 6.5 nm

Ribosome 25 nm

definition of nanotechnology
From NNI (National Nanotechnology Initiative) The Initiative and its Implementation Plan :

The essence of nanotechnology is the ability to work at the molecular level, atom by atom, to create large structures with fundamentally new molecular organization. Compared to the behavior of isolated molecules of about 1 nm (10 -9 m) or of bulk materials, behavior of structural features in the range of about 10 -9 to 10 -7 m (1 to 100 nm - a typical dimension of 10 nm is 1,000 times smaller than the diameter of a human hair) exhibit important changes. Nanotechnology is concerned with materials and systems whose structures and components exhibit novel and significantly improved physical, chemical, and biological properties, phenomena, and processes due to their nanoscale size.

Definition of Nanotechnology:
national technology for the 21 st century leading to a new industrial revolution
National technology for the 21st century: Leading to a new industrial revolution
  • Initiatives (NTR):
  • Research on fundamental understanding and discoveries.
  • Design of nanostructured materials.
  • Nanodevices: information, bio, medical.
  • Applications of nanomaterials and devices to energy, health, evironment, and security.
  • Education of a new generation of skilled workers.
history of nni national nanotechnology initiative
History of NNI: (National Nanotechnology Initiative)
  • 1998: IWGN (Interagency Working Group on Nanotechnology)—National technology for the 21st century: Leading to a new industrial revolution.
  • 2001: NNI (Nantional Nanotechnology Initiative)—Funding at ~500 million.
  • 2001 NSET (National Science, Engineering, and Technology)
nanostructured materials
Nanostructured Materials:
  • Carbon nanotubes
  • Aerogels
  • Zeolites
  • Dendrimers
  • Self-assembled monolayers
  • Nanoparticles
  • Nanowires
  • NEMS, etc.
applications of nanotechnology
Applications of nanotechnology:
  • A new industrial revolution (on the scale of the transistors in 1950s).
  • Potentially it will pervade all sectors of industry and technology.
  • Essentially in the following areas:

Information, health, space, environment, defense, etc.

mimicry of nature 1 the lotus effect
Mimicry of Nature—1 The Lotus Effect

Water runs off.

  • Both surface chemistry and surface topology influence the hydrophobicity -slip. The surface contains “waxy bumps”.
  • Using the “Lotus effect” (that lotus leaves are highly hydrophobic), one can achieve slip flow (Tretheway & Meinhart –UCSB, Silane. Phys. Fluids 2002).

Water beads up on papillae.

Papillae on leaves.

mimicry of nature 3 water strider
Mimicry of Nature—3Water Strider

Gao, X. F. & Jiang, L. Water-repellent legs of water striders. Nature432, 36 (2004).

μ

nanosensors20
Nanosensors:
  • Using nanostructued materials for detection of trace amounts of chemical and biological agents. (Medical, space, environmental, homeland security).
antimicrobial nanoemulsion james baker u michigan
Antimicrobial Nanoemulsion(James Baker, U. Michigan)
  • Use of soybean oil emulsified with surfactants. Drops ~400 – 600 nm.
  • The droplet do not coalesce with themselves . High surface tension make them coalesce with other lipid droplets, killing bacteria.
  • Safe for external use. Not safe for red cells, or sperm.
slide26
The droplets fuse with cell membrane of microorganisms resulting in cell lysis.
  • Very effective in killing:

– Bacteria, 

– Bacterial spores, 

– Enveloped viruses, and

– Fungal spores.

  • They are effective at preventing illness in individuals, when used both before and after exposure to the infective agent.
  • They could be used: 

– Topically, 

– As an inhalant.

antimicrobial nanoemulsion
Antimicrobial Nanoemulsion
  • Left: treated with nanoemulsion,
  • Right: untreated.
  • The growth of bacteria colonies has been eliminated by treatment with the nanoemulsion.
generations of dendrimers
Generations of Dendrimers

2nd gen.

5th gen.

4th gen.

pamam dendrimer polyamidoamine
PAMAM Dendrimer (polyamidoamine)
  • Alternating

(B)-AB-AB-AB-...

  • Ethylenediamine (B)
  • H2N-C-C-NH2
  • Methylacrylate (A)
  • C=C-CO-OCH3
pamam moieties
PAMAM Moieties:

Diamine

Acrylate

NH3 or Diamine

size of pamam dendrimers generation m w angstrom dia end gps
Size of PAMAM DendrimersGeneration M.W. Angstrom (dia.) End Gps

(1 nm = 10 Angstroms)

applications of dendrimers
Applications of Dendrimers
  • Gas and chemical sensors
  • Catalysts
  • Drug delivery and gene therapy
  • Surface modifiers (tribology, and information storage)
  • Bio compatible materials
  • Electronic devices and antennae
james r baker jr university of michigan
James R. Baker Jr. University of Michigan

Professor, Internal Medicine and Bioengineering

Chief, Division of Allergy

Director, Center for Biologic Nanotechnology

Co-Director, Center for Biomedical Engineering

Biotechnology, Nanotechnology and Immunology

slide41
Drug Delivery
  • Research in the area of autoimmune endocrine disease. He has helped define the basis of the autoimmune response to thyroid auto antigens.

Gene Delivery

  • Work concerning gene transfer; developing a new vector system for gene transfer using synthetic polymers (dendrimers).

Anti-microbial research

  • Work on preventing pathogens from entering the human body. This research project seeks to develop a composite material that will serve as a pathogen avoidance barrier and post-exposure therapeutic agent to be applied in a topical manner to the skin and mucous membranes.
drug delivery by dendrimers
Dendrimers

(code named “smart bombs”)

Targeting cancer cells (ignore normal ones)

Able to enter cells

Little toxicity

Focus:

High energy lasers or sound wave to trigger the release of the drug out of the dendrimer.

Drug Delivery by Dendrimers
polyfunctional tecto dendrimers connected pamam units
Polyfunctional Tecto-dendrimers: (connected PAMAM units)
  • Each “spore” in this “smart bomb” has its function:
  • Sensing and binding the target (cancer cells).
  • Emitting a signal (imaging).
  • Drug delivery in situ.
  • Dendrimer’s structure tricks the immune system, avoiding response.
  • Low toxicity
types of carbon nanotubes
Types of Carbon Nanotubes:

1.Armchair. 2. Zigzag. 3. Chiral

a graphene sheet
A Graphene Sheet

n=m  Armchair. m=0  Zigzag. others  Chiral.

nanofluidics examples of mems nems micro nano electromechanical systems
Nanofluidics :Examples of MEMS & NEMS: (Micro- & Nano-electromechanical systems)

Lieber (Harvard)

laboratory on a chip
(“Laboratory-on-a chip”)

Lieber (Harvard)

MEMS

flow behavior in nanofluidics 2
Flow behavior in nanofluidics: (2)
  • LOCOMOTION?

difficult to make fluid flow in small channels.

  • Driving forces:
  • Pressure
  • Surface-capillary force
  • Electric (electroosmotic, electrophoretic, electrohydrodynamic, electrowetting), and magnetic (magnetohydrodynamic)
  • Sound—acoustic
  • Centrifuge (rotation)
making circuitry by nanofluidics lieber harvard
Making Circuitry by Nanofluidics:(Lieber, Harvard)

Purpose: using viscous flow in nanochannels.

to orient and assemble nanowires (to make logical circuitries).

Note: at nanoscale, the surface effects are large (due to large surface-to-volume ratio). Thus viscous forces dominate in the flow.

slide69

(1) Make a mold of channels (PDMS-polydimethylsiloxane). (2) Disperse nanowires (GaP, InP, Si) in ethanol, the carrier solvent. (3) Flow the suspension through the nanochannels.

what happens to the flow when the interface is hydrophobic slip
What happens to the flow when the interface is hydrophobic? --Slip

2002 Phys. Fluids

Velocity at wall is 10% of the center (NOT zero, i.e. Slip). This increases the total volumetric flow.

topics continued
TOPICS: continued
  • High-performance computing (Dr. Neeman)
  • Experimental program (Dr. Newman)
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