ueet 102 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
UEET 102 PowerPoint Presentation
Download Presentation
UEET 102

Loading in 2 Seconds...

play fullscreen
1 / 34

UEET 102 - PowerPoint PPT Presentation


  • 395 Views
  • Uploaded on

UEET 102 Lecture 1 Introduction to Geologic Materials and Nanotechnology Review of terminology Nanotechnology and Geosciences Mineral formation and properties Crystal Growth Concept of a lattice Lecture 2 – Asbestos Form Minerals What is asbestos?

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'UEET 102' - Samuel


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
ueet 102

UEET 102

Lecture 1 Introduction to Geologic Materials and Nanotechnology

Review of terminology

Nanotechnology and Geosciences

Mineral formation and properties

Crystal Growth

Concept of a lattice

Lecture 2 – Asbestos Form Minerals

What is asbestos?

Comparing and contrasting silicate structures

Phyllosilicates and double chain silicates

Asbestos health hazards

Lecture 3 – Clays and Nanotechnology

Crystal structure

Crystal Morphology

Properties due to morphology and crystal structure

Use and case study

ueet 1022

UEET 102

Lecture 1 – Introduction

Review of terminology

Nanotechnology and Geosciences

Mineral formation and properties

Crystal Growth

Concept of a lattice

slide4

Nanotechnology in Geology

  • What are some applications of nanotechnology in geology (or: How can nanotechnology benefit from geology?).
  • Nanotechnology goes underground to boost oil production.
    • http://www.nanowerk.com/news/newsid=4084.php
  • Typically 60 percent of oil remains underground after primary, secondary and in some cases even tertiary recovery methods.
  • Will develop intelligent subsurface micro and nanosensors that can be injected into oil and gas reservoirs to help characterize the space (chemical and physical characteristics of existing oil and gas reservoirs) in three dimensions and improve the recovery of existing and new hydrocarbon resources.
slide5

Nanotechnology in Geology

  • Nanotechnology goes underground to boost oil production.
    • http://www.nanowerk.com/news/newsid=4084.php
  • Typically 60 percent of oil remains underground after primary, secondary and in some cases even tertiary recovery methods.
  • Will develop intelligent subsurface micro and nanosensors that can be injected into oil and gas reservoirs to help characterize the space (chemical and physical characteristics of existing oil and gas reservoirs) in three dimensions and improve the recovery of existing and new hydrocarbon resources.
slide6

Nanotechnology in Geology

  • Future nanotech tools made from clay
    • Rochester, N.Y.-based company has found a way to use Halloysite, a naturally occurring tubular clay, as an unobtrusive carrier in metals, perfumes and other substances (http://news.cnet.com/Future-nanotech-tools-made-from-clay/2100-11390_3-5914034.html).
  • Halloysite - Al2Si2O5(OH)4
  • Nanotech clay armor creates fire resistant hard wearing latex emulsion paints (http://www.physorg.com/news104666616.html)
  • Laponite clays
  • Discs are 1 nm thick by 25 nm in diameter
slide7

Minerals

  • A mineralis a crystalline solid, formed by natural geological processes, with a specific chemical composition.
  • Form in the geosphere (most minerals), hydrosphere (e.g., halite), biosphere (e.g., calcite), and even the atmosphere (e.g., water ice, as snow)
  • Consistent and recognizable physical and chemical properties
slide8

Minerals

  • A mineral must meet the following criteria:
    • Crystalline solid
      • Atoms are arranged in a consistent and orderly geometric pattern
    • Forms through natural geological processes
    • Has a specific chemical composition
  • Rock-forming minerals
    • Although over 4000 minerals have been identified, only a few hundred are common enough to be generally important to geology (rock-forming minerals)
    • Over 90% of Earth’s crust is composed of minerals from only 5 groups (feldspars, pyroxenes, amphiboles, micas, quartz)
important ions in minerals
Important ions in minerals
  • When an atom loses or gains an electron to or from another atom it is called an ion.
    • Positively charged ions (loss of electron) are cations.
    • Negatively charged ions (gain of electron) are anions.

anions charge cations charge

Si +4

K +1

Ca +2

Na +1

Al +3

Mg +2

Fe +2 or +3

O −2

bonding and atomic arrangement
Bonding and Atomic Arrangement

Atomic structure of diamond (C)

Atomic structure of graphite (C)

slide13

Composition of Earth’s Crust

  • Minerals have crystalline structures
    • Regular 3-D arrangement of atoms
    • d-spacings range from 0.7 to 24 Å (0.07 to 2.4 nm).
crystal structure
Crystal Structure
  • Anions are generally larger than cations
  • Structure of mineral determined largely by how the anions are arranged and how the cations fit between them.
slide15

Silicate Structures

  • The Silicon-Oxygen tetrahedron
    • Strongly bonded silicate ion
    • Four oxygens surrounding a silicon ion
    • Basic structure (tetrahedra) for silicate minerals
slide17

Silicate Structures

  • Sharing of O atoms in tetrahedra
    • The more shared O atoms per tetrahedron, the more complex the silicate structure
slide18

Silicate Structures

  • Sharing of O atoms in tetrahedra
    • Isolated tetrahedra (none shared)
    • Chain silicates (2 shared)
    • Double-chain silicates (alternating 2 and 3 shared)
    • Sheet silicates (3 shared)
    • Framework silicates (4 shared)
slide19

Non-silicate Minerals

  • Carbonates
    • Contain CO3 in their structures (e.g., calcite - CaCO3)
  • Sulfates
    • Contain SO4 in their structures (e.g., gypsum - CaSO4.2H2O)
  • Sulfides
    • Contain S (but no O) in their structures (e.g., pyrite - FeS2)
  • Oxides
    • Contain O, but not bonded to Si, C or S (e.g., hematite - Fe2O3)
  • Hydroxides
    • Contain OH, but not bonded to Si, C or S (e.g., brucite – Mg(OH)2)
  • Native elements
    • Composed entirely of one element (e.g., diamond - C; gold - Au)
polymorphs
Polymorphs
  • Minerals with the same chemical composition, but different structure.
    • diamond and graphite – C
    • andalusite, kyanite, and sillimanite – Al2SiO5
slide21

Mineral Properties

  • Color
    • Visible hue of a mineral
  • Streak
    • Color left behind when mineral is scraped on unglazed porcelain
  • Luster
    • Manner in which light reflects off surface of a mineral
  • Hardness
    • Scratch-resistance
  • Crystal form
    • External geometric form
  • Cleavage
    • Breakage along flat planes
  • Fracture
    • Irregular breakage
  • Specific gravity
    • Density relative to that of water
  • Magnetism
    • Attracted to magnet
  • Chemical reaction
    • Calcite fizzes in dilute HCl
thought exercise
Thought Exercise
  • Diamond and graphite are polymorphs of C, why are their properties so different?
  • What are the uses of diamond and graphite and why do they differ?
slide23

Lattice and Unit Cell Concepts

  • Are these Lego blocks the same?
  • Would a structure made of yellow blocks look the same as one made of yellow and white?
  • Can we define a large structure by looking at a smaller subset of the structure?
slide24

Lattice and Unit Cell Concepts

  • In 1784 René Haüy came up with an explanation for growth morphology and regular cleavage planes.
  • He proposed that crystals are built up from elementary parallelepipeds (a polyhedron consisting of three pairs of parallel faces) filling up spaces without gaps.
  • Parallelepipeds are idealized unit cells (the basic repeating unit that can generate an entire crystal structure).

SEM image of europium-tellurium alloy

crystal morphology and symmetry

Crystal Morphology and Symmetry

The symmetry of crystal faces is due to the ordered internal arrangement of atoms, this is called a lattice.

In 2-dimensions a plane lattice consists of an orderly array of points defined by the spacing and angles between points.

The array can be reproduced by specifying the distance and angle from point to point.  This is referred to as translational symmetry.

3-dimensional arrays are called space lattices.

nucleation

Let’s start at the beginning!

  • Nucleation – The onset of a phase transition in a small but chemically stable domain.
    • Bubbles of carbon dioxide nucleate shortly after the pressure is released from a container of carbonated liquid.

Nucleation

nucleation28

Nucleation can occur in the interior of a uniform substance, by a process called homogeneous nucleation.

    • This requires a lot of energy and is fairly difficult.
  • Nucleation often occurs more easily at a pre-existing interface (heterogeneous nucleation), as happens on boiling chips and prexisting mineral phases.

Nucleation

crystal growth

What is crystal growth and crystallization?

    • Crystal growth is part of the crystallization process and represents changing chemical stability.

Crystal Growth

crystal growth30

What is crystal growth and crystallization?

  • What factors can influence crystal growth?

Crystal Growth

  • Pressure
    • +differential P
  • Temperature
    • ° of undercooling
  • Time/Growth Rate
  • Solution dynamics
  • Interface controls
  • All of this relative to equilibrium of a phase
crystal growth31

What is crystal growth?

Crystal Growth

  • Sketch to illustrate the effect of relative growth rates on the dominance of faces. Faces with the slowest growth rate dominate the morphology. (a) Slower growing faces p and s begin to dominate face m. (b) Faces p and s are dominate by slower growing face m.
crystal morphology and symmetry32

Crystal Morphology and Symmetry

Crystal faces develop along planes defined by the points in the lattice.

All crystal faces must intersect atoms or molecules that make up the points.

Observation:

The frequency with which a given face in a crystal is observed is proportional to the density of lattice nodes along that plane

A face is more commonly developed in a crystal if it intersects a larger number of lattice points. This is known as the Bravais Law.

crystal morphology
Crystal Morphology
  • Because faces have a direct relationship to the internal structure, they must have a direct and consistent angular relationship to each other
  • Nicholas Steno (1669): Law of Constancy of Interfacial Angles

Quartz

thought exercise34
Thought Exercise
  • In what ways can we emphasize favorable nanotechnology properties through controls on crystal formation?
    • What can Geology teach us?