Nanotechnology in Building and Construction

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SESSION 1
Nanotechnology in Building and Construction
Joannie ChinLeader, Polymeric Materials
GroupNational Institute of Standards and
Technology
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NIST Mission

• To promote U.S. innovation and industrial
  competitiveness by advancing
• measurement
• science,
• standards, and
• technology
• in ways that enhance economic security and
  improve our quality of life.
• www.nist.gov

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The NIST Laboratories
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Nanostructured Materials

• At least one dimension is between 1 and 100 nm.
• Can contain nanoparticles, or have a structural
  component with nanoscale dimensions (thickness,
  crystal size, etc).
• Nanoparticles
• TiO2, ZnO2
• Fullerenes
• Carbon nanotubes
• Silica
• Alumina
• Magnesium, calcium
• Clays

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Nanostructured Materials

• Gaining control of materials at the nanoscale
  brings different laws of physics into play.
• Traditional materials show radically enhanced
  properties when engineered at the nanoscale.

Source Bell 2006
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• The construction industry was the only industry
  to identify nanotechnology as a promising
  emerging technology in the UK Delphi Survey in
  the early 1990s
• However, construction has lagged behind other
  industrial sectors, such as automotive,
  chemicals, electronics and biotech sectors, where
  nanotechnology RD has attracted significant
  interest and investment from large industrial
  corporations and venture capitalists.
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• Application of Nanotechnology in Construction,
  Materials and Structures, 37, 649 (2004).

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Nanomaterials in Construction

• At present, nearly 500 consumer products in 20
  countries contain nanomaterials 50B worth of
  nanomaterials sold in 2006.
• It is projected that by 2010, nanocomposite usage
  will grow to gt 340 million pounds, and gt 7
  billion pounds in 2020.

Source Fredonia Group, 2007
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Nanomaterials in Construction

• Deterioration of U.S. infrastructure
• Cost of repairs is estimated to exceed 2
  trillion (NRC, ASCE)
• Housing is plagued with poor
  material quality and excessive
  fire losses that have led to
  
  premature failure, loss of life,
  as well as annual repair
  costs exceeding 60
  billion.
• Nanotechnology offers tremendous potential for
  improving building materials.

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Cement and Concrete

• Nano silica and clinker, as well as nanofibers,
  used to increase mechanical properties and
  durability of cementitious materials.
• Service life can be doubled through the use of
  nano-additives (patent pending)
• Photocatalytic TiO2 added to concrete to reduce
  carbon monoxide and NOx emissions on roadways.

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Carbon Nanotubes

• Heralded as one of the Top ten advances in
  materials science over the last 50 years,
  Materials Today, 2008.
• Sales of CNTs projected to
• exceed 2B, gt103 metric tons annually in the
  next 4 - 7 years.
• Major use electronics and composites.

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Thermal Insulation

• Nanoporous silica foam, containing 5- 50 nm
  diameter internal pores.
• Super-insulating, lightweight structural material.

• A 1-inch thick piece is a better insulator than
  20 evacuated thermalpane windows.

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Coatings - Organic

• Projected to make up 73 of nanocomposites
  market by 2010 (Freedonia Group)
• Thin film, clear nanocomposites for improved
  scratch and mar properties.
• Antimicrobial, self-cleaning surfaces.
• Smart coatings Sense pressure, impact, damage,
  chemicals, heat, light, etc.

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Coatings - Inorganic
Self-cleaning glass Nano-TiO2 coated
glass
window glass
conventional glass
self-cleaning glass
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Photovoltaics

• Predominant photovoltaic material is silicon, but
  an emerging technology involves the use of
  dye-sensitized nano-TiO2.
• Large surface area of nano TiO2 greatly increases
  photovoltaic efficiency.
• Potential for lower material and processing costs
  relative to conventional solar cells.

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Nanoadditive Fire Retardants

• Use of nanoadditive fire retardants prompted by
  bans on halogenated flame retardants enacted in
  many states.
• Polymer nanocomposites filled with clay, CNTs,
  etc., possess improved flammability resistance
  while maintaining or improving mechanical
  properties.
• Reduces heat release rate during fire event by
  formation of surface char which insulates
  underlying material.

Heat Flux
Heat Flux
Poor Dispersion
Good Dispersion
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Challenges

• Techniques for dispersing nanofillers AND
  measuring degree of dispersion.
• Measurement of adhesion and interfacial
  properties.
• Chemical and mechanical measurements at the
  nanoscale.
• Prediction of nanocomposite properties and
  service life over a wide range of length scales.
• Unknown health and environmental effects
  virgin, released material.

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Challenges
What do you perceive as the biggest risk or
barrier to nanotechnology in the construction
industry?
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Questions?

• Contact Joannie Chin
• Joannie.Chin_at_nist.gov
• slp.nist.gov
• bfrl.nist.gov