UEET 102

1
UEET 102

• Lecture 3 Clays and Nanotechnology
• Test 10 or so questions to be given?

2
Sheet Silicates (Phyllosilicates)

• Serpentine Group
• Antigorite Chrysotile Lizardite
  Mg3Si2O5(OH)4
• Clay Mineral Group
• Kaolinite Al2Si2O5(OH)4
• Halloysite Al2Si2O5(OH)4 to Al2Si2O5(OH)42H2O
• Talc Mg3Si4O10(OH)2
• Pyrophyllite Al2Si4O10(OH)2
• Laponite Industrial
• Bentonite-Montmorillonite (Al,Mg)8(Si4O10)4(OH)8
  12H2O

3
Clay Mineral Formation

• Most sheet silicates are low-pressure and
  low-temperature minerals. Only the micas can
  occur in igneous rocks.
• Clay minerals form directly by precipitation from
  seawater and by alteration (weathering processes)
  of primary minerals.

• The production of clay minerals requires the
  addition of water as OH (this is sometimes
  called hydration or hydrolysis (improper)).

• Wet and warm climates will produce a greater
  proportion of clay minerals.

4
Clay Minerals
Serpentine (t-o layering)
Talc (t-o-t layering)
OH replaces O in octahedra
5
(No Transcript)
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Kaolinite Al2Si2O5(OH)4

• Crystallography
• Triclinic 1
• t-o layers

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Kaolinite Al2Si2O5(OH)4

• Very difficult to distinguish from other clays
  without X-ray analysis
• Occurrence
• Formed from alteration of other minerals
• One of the most common products of weathering
• ABUNDANT
• Very small grain size!

8
Kaolinite Al2Si2O5(OH)4

• Use
• Chief component of kaolin or clay
• Used in the manufacture of brick, drain tile,
  sewer pipe (old times), china and pottery.
• Largest market is as a filler in paper, but also
  used in the rubber and refractory industries
• Can be molded easily when wet and then heated to
  drive off the water and form a hardened durable
  material.

Al2Si2O5(OH)4 ? Al2SiO5 SiO2 2H2O
9
Halloysite

• Al2Si2O5(OH)4 to Al2Si2O5(OH)42H2O
• A naturally occurring tubular clay with a similar
  formula to kaolinite

10
Nanotechnology and Halloysite

• A naturally occurring tubular clay (cheap,
  purchase by the ton)
• Similar shaped carbon nantubes are 250 per gram
• Used as an unobtrusive carrier in metals,
  perfumes and other substances.
• http//news.cnet.com/Future-nanotech-tools-made-fr
  om-clay/2100-11390_3-5914034.html

11
Nanotechnology and Laponite

• Laponite clays industrial/synthetic clay
• Latex emulsion paints use soap to counteract the
  polymer part of the paints aversion to water.
• Nanotech clay armor creates fire resistant hard
  wearing latex emulsion paints (http//www.physorg.
  com/news104666616.html)
• Why is it fire resistant?

12
Nanotechnology and Laponite

• Laponite clays industrial/synthetic clay
• Latex emulsion paints use soap to counteract the
  polymer part of the paints aversion to water.
• Nanotech clay armor creates fire resistant hard
  wearing latex emulsion paints (http//www.physorg.
  com/news104666616.html)
• Why is it fire resistant?

Al2Si2O5(OH)4 ? Al2SiO5 SiO2 2H2O
13
Nanotechnology in Geology

• Bentonite-Montmorillonite Clays
• (Al,Mg)8(Si4O10)4(OH)812H2O

Large open spaces in the structure!
14
Nanotechnology in Geology

• Bentonite-Montmorillonite Clays
• (Al,Mg)8(Si4O10)4(OH)812H2O
• Disinfectant, desiccant, and water and air
  purification filtering
• Environmental decontamination
• Why is this effective?

15
Nanotechnology in Geology

• Bentonite-Montmorillonite Clays
• Construction materials
• Nanocomposites for new high-tech polymer materials

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Nanotechnology and Clay Minerals

• What is it about clays that make them so useful
  in nanotechnology?
• What is the underlying reason for this?

17
Nanotechnology and Clay Minerals

• Why clays instead of other materials?
• Form at low temperatures and pressure.
• Can influence growth easily (platelet size).

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Nanotechnology and Clay Minerals

• Why clays instead of other materials?
• Form at low temperatures and pressure.
• Can influence growth easily (platelet size).

An explosion sends shock waves through Belvidere
and kills a man with flying debris. It happened
around 230 p.m. at NDK America, 701 Crystal
Parkway. Belvidere Fire Chief Dave Worrell says a
pressure chamber gave way. The chamber was
pressurized to 27,000 p.s.i., he said, and used
to make synthetic crystals for computers. NDK
makes crystals used in computers, telephones,
liquid crystal displays and other electronics.
http//www.wrex.com/Global/story.asp?S11634956
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Nanotechnology and Clay Minerals

• Why clays instead of other materials?
• Form at low temperatures and pressure.
• Can influence growth easily.
• What does the future hold?

20
Nanotechnology and Silicates

• Spray-on liquid glass is transparent, non-toxic,
  and can protect virtually any surface against
  almost any damage from hazards such as water, UV
  radiation, dirt, heat, and bacterial infections.
  The coating is also flexible and breathable,
  which makes it suitable for use on an enormous
  array of products

21
Nanotechnology and Silicates

• Spray-on liquid glass is transparent, non-toxic,
  and can protect virtually any surface against
  almost any damage from hazards such as water, UV
  radiation, dirt, heat, and bacterial infections.
  The coating is also flexible and breathable,
  which makes it suitable for use on an enormous
  array of products

Problem?
22
Nanotechnology and Silicates

• The liquid glass spray (technically termed
  SiO2 ultra-thin layering) is extracted from
  quartz sand. Water or ethanol is added. There are
  no other additives, and the nano-coating bonds to
  the surface because of quantum forces. According
  to the manufacturers, liquid glass has a
  long-lasting antibacterial effect because
  microbes landing on the surface cannot divide or
  replicate easily.
• To what is this similar?

23
Nanotechnology and Silicates

• The liquid glass spray (technically termed
  SiO2 ultra-thin layering) is extracted from
  quartz sand. Water or ethanol is added. There are
  no other additives, and the nano-coating bonds to
  the surface because of quantum forces. According
  to the manufacturers, liquid glass has a
  long-lasting antibacterial effect because
  microbes landing on the surface cannot divide or
  replicate easily.
• To what is this similar?
• Opal - SiO2 nH2O
• Water content ranges between
• 4 and 9 wt., but can range up
• to 20 wt.